Past Papers (2, 4 & 6)
Classified According to
The Syllabus
Mrs. Maha Faried
‫ ﻋﻤﺮو ﺧﺎﻟﺪ ﻗﻨﺪﯾﻞ‬.‫ﺻﺪﻗﮫ ﺟﺎرﯾﮫ ﻟﺮوح اﺑﻨﻰ اﻟﻤﺮﺣﻮم ﺑﺎذن ﷲ د‬
Topic 1: The particulate nature of matter
• States of matter
• Kinetic particle theory
• Diffusion
Topic 2: Experimental techniques
•
•
•
•
•
Laboratory apparatus
Safety in laboratory
Methods of purification
Separation of mixtures
Chromatography
Topic 3: Atoms, elements and compounds
•
•
•
•
•
•
Atomic structure
Radioactive isotopes
Electron distribution
Ions and ionic bonds
Molecules and covalent bonds
Macromolecular (giant) structures
Topic 4: Stoichiometry
•
•
•
•
•
•
Chemical formula
Chemical equation
Chemical calculations
The mole
Empirical formula and molecular formula
Macromolecular (giant) structures
Topic 5: The periodic table
•
•
•
•
•
•
Trend in group I (The alkali metals)
Transition metals
Trend in group VII (The halogens)
Nobel gases
Test and collection of gases
Oxidation and reduction
Topic 6: Electricity and chemistry
•
•
Electrolysis
Applications of electrolysis
Topic 7: Acids, bases and salts
•
•
•
•
•
•
Acids
Bases
The pH Scale
Making salts
Types of oxide
Identification of ions
Topic 8: Metals and reactivity series
• Alloys
• Reactivity series
• Extraction of iron and steel making.
• Extraction of zinc
• Rusting
Topic 9: Chemical changes
• Production of energy
• Electricity from chemical reaction
Topic 10: Chemical reactions
• Speed of reaction
• Reversible reaction
• Chemical equilibrium
Topic 11: Air and water
•
•
•
•
•
Purification of water supply
Composition of air
Manufacture of ammonia
Fertilizers
Air pollution
Topic 12: Carbonates
Topic 13: Sulfur
Topic 14: Organic chemistry
IGCSE
Grade (10)
Topic 1
The particulate nature of matter
• States of matter
• Kinetic particle theory
• Diffusion
IGCSE
Grade (10)
Paper 2
1. Diagrams 1, 2 and 3 represent the three states of matter.
J. 02
(2)
For which states can diffusion be demonstrated by using simple laboratory apparatus?
A
1 only
B
1 and 2
C
2 and 3
D
1, 2 and 3
2. Heating a liquid causes it to become a vapour.
What happens to the molecules of the liquid during this process?
N. 02
(1)
IGCSE
Grade (10)
3. Some sugar is dissolved in water.
N. 02
(2)
Which diagram shows how the particles are arranged in the solution?
4. A solid metal is heated until it turns to vapour.
The graph shows the temperature of the metal during this process.
J. 03
(2)
Which part of the graph shows the melting of the metal?
5. Some students are asked to describe differences between gases and liquids.
Three of their suggestions are:
J.04 (1)
Which suggestions are correct?
A. 1 only
B. 2 only
C. 3 only
D. 1, 2 and 3
IGCSE
6.
Grade (10)
J. 04 (2)
A coloured liquid vaporises easily at room temperature. Some of the liquid is placed at the
bottom of a sealed gas jar.
Which diagram shows the appearance of the jar after several hours?
7. The melting points and boiling points of four substances are shown.
N. 04 (2)
Which substance is liquid at 100 oC ?
8. At room temperature, in which substance are the particles furthest apart?
A. H2
B. H2O
C. Mg
D. MgO
J. 06 (1)
IGCSE
Grade (10)
J. 07
9. When there is no wind, the scent of flowers can be detected more easily on a warm
evening than on a cold evening.
(1)
This is because the molecules of the scent ……1…… ……2…… than in colder conditions.
Which words correctly complete gaps 1 and 2?
10.
J. 08
(1)
A yellow precipitate is formed in the experiment shown.
How is the precipitate formed?
A. Particles collide, diffuse and then react.
B. Particles collide, react and then diffuse.
C. Particles diffuse, collide and then react.
D. Particles diffuse, react and then collide
11. In which substance are the particles furthest apart at room temperature?
A.
B.
C.
D.
ethanol
methane
salt
sugar
N. 08
(1)
IGCSE
Grade (10)
J. 09
12. The diagram shows how the molecules in the exhaust gases diffuse into the air.
(1)
Which statement describes what happens to these molecules next?
A.
B.
C.
D.
The molecules fall to the ground because they are heavier than air molecules.
The molecules go back together as they cool.
The molecules spread further into the air.
The molecules stay where they are.
13. The diagram shows a cup of tea.
J. 10
Which row describes the water particles in the air above the cup compared with the
water particles in the cup?
(1)
IGCSE
Grade (10)
Paper 4
1.
J. 02 (5. a, b)
(a) The Kinetic Theory explains the properties of solids, liquids and gases in terms of the
movement of particles.
Liquids and gases both take up the shape of the container but a gas always fills the
container. Explain this, using the ideas of the Kinetic Theory.
……..............................................................................................................................................
….…............................................................................................................................................
………......................................................................................................................................[4]
(b) The following apparatus can be used to measure the rate of diffusion of a gas.
(i) What measurements would need to be taken to calculate the rate of diffusion of a
gas?
……………...................................................................................................................................
.................................................................................................................................................[2]
IGCSE
Grade (10)
(ii) Which gas, carbon dioxide or sulfur dioxide, would diffuse faster?
Explain your choice.
……….........................................................................................................................................
……………...............................................................................................................................[3]
2.
J.03 (4. b)
(b) When nitrogen dioxide is cooled, it forms a yellow liquid and then pale yellow crystals.
These crystals are heated and the temperature is measured every minute. The
following graph can be drawn.
(i)
Describe the arrangement and movement of the molecules in the region A–B.
....................................................................................................................................................
....................................................................................................................................................
(ii) Name the change that occurs in the region B–C
.................................................................................................................................................[4]
IGCSE
3.
Grade (10)
N 05 (2. a)
Ethanoic acid is a colourless liquid at room temperature. It has the typical acid properties
and forms compounds called ethanoates.
(a) A pure sample of ethanoic acid is slowly heated from 0oC to 150oC and its temperature
is measured every minute. The results are represented on the graph below.
(i) Name the change that occurs in the region D to E.
……………………………………………………………………………………………………… [1]
(ii) What would be the difference in the region B to C if an impure sample had been
used?
………………………………………………………………………………………………………..[1]
(iii) Sketch on the graph how the line would continue if the acid was heated to a higher
temperature.
[1]
IGCSE
Grade (10)
Topic 2
Experimental techniques
• Laboratory apparatus
• Safety in laboratory
• Methods of purification
• Separation of mixtures
• Chromatography
IGCSE
Grade (10)
Paper 2
1. How can crystals be obtained from a hot, concentrated solution of a salt?
A.
B.
C.
D.
J.02
(3)
by adding cold water
by cooling and then filtering
by filtering only
by filtering and drying the residue
2. The diagrams show a cooling experiment and the results.
What liquid could X be?
J. 02
(4)
IGCSE
Grade (10)
3.
N. 02
Some paraffin is contaminated with soot (carbon). The soot is removed as shown.
(4)
Which method is used to remove the soot?
A.
B.
C.
D.
cracking
crystallisation
diffusion
filtration
4. The diagram shows how to obtain pure water from seawater.
Where do water molecules lose energy?
J. 03
(1)
IGCSE
Grade (10)
5. Some chemical compounds are purified by recrystallisation.
J. 03
(3)
What can be used to test the purity of the crystals?
A. melting point
B. colour of crystals
C. size of crystals
D. Solubility
6.
J. 03
(4)
What could be the melting point and boiling point of water containing a dissolved impurity?
7. The diagram shows a chromatogram obtained from three sweets, X, Y and Z.
How many different red dyes are present in the sweets?
A. 1
B. 2
C. 3
D. 4
N. 01 (4)
J. 04 (4)
IGCSE
Grade (10)
8.
N. 04 (3)
The apparatus shown cannot be used to determine the melting point of sodium chloride,
NaCl
Why is this?
9. In an experiment, a student needs to measure out 36.50 cm3 of a solution.
Which piece of apparatus would measure this volume most accurately?
A.
B.
C.
D.
beaker
burette
measuring cylinder
Pipette
J. o5
(3)
IGCSE
10.
Grade (10)
N. 05
(3)
A coin is dissolved in an acid. Chromatography is used to test the solution formed. The
diagram shows the chromatogram obtained.
What is the coin made from?
A.
B.
C.
D.
11.
a metal element
a non-metal element
a mixture of metals
a mixture of non-metals
J. 07 (3)
The boiling point of liquid X is lower than that of water. To test a student, a teacher covers
up the numbers on a thermometer. The student places the thermometer in boiling liquid X.
The diagram represents part of the stem of this thermometer.
What could the temperature on the thermometer be?
A 75.5 C
B 84.5 C
C 104.5 C
12. Part of the instructions in an experiment reads as follows.
Quickly add 50 cm3 of acid.
What is the best piece of apparatus to use?
A. a burette
B. a conical flask
C. a measuring cylinder
D. a pipette
D 105.5 C
N. 07
(2)
IGCSE
13.
Grade (10)
N. 07
(4)
A sample of a drug is analysed by using a chemical test for aspirin and measuring its
melting point.
The chemical test is positive but the melting point is 130 °C not 135 °C as it should be.
What is correct?
14.
J. o8
(2)
A student is asked to measure the time taken for 4.00 g of magnesium carbonate to react
completely with 25.0 cm3 (an excess) of dilute hydrochloric acid.
Which pieces of apparatus does the student need?
A.
B.
C.
D.
15.
balance, clock, pipette
balance, clock, thermometer
balance, pipette, thermometer
clock, pipette, thermometer
J. 08
Chromatography and fractional distillation can be used to separate compounds.
In which type of separation is a thermometer needed for checking that complete
separation has occurred?
A.
B.
C.
D.
chromatographic separation of two colourless solids
chromatographic separation of two solids of different colours
fractional distillation of two colourless liquids
fractional distillation of two liquids of different colours
(3)
IGCSE
Grade (10)
16.
N. 08
(2)
An experiment is carried out to separate a mixture of two dyes. A line is drawn on a piece of
chromatography paper and a spot of the dye mixture placed on it. The paper is dipped into a
solvent and left for several minutes.
Which statement about this experiment is correct?
A. The dyes must differ in their boiling points.
B. The dyes must differ in their solubilities in the solvent.
C. The line must be drawn in ink.
D. The line must be placed below the level of the solvent.
17.
J. 09
(3)
The diagram shows the paper chromatograms of four substances, W, X, Y and Z.
Which two substances are pure?
A. W and X
B. W and Y
C. X and Y
D. X and Z
IGCSE
18.
Grade (10)
J. 2010 ( 2)
A student carries out an experiment to find how fast 3 cm pieces of magnesium ribbon
dissolve in10 cm3 samples of sulfuric acid at different temperatures.
Which piece of apparatus does the student not need?
A. balance
B. measuring cylinder
C. stop-clock
D. thermometer
19.
N. 2010 (2)
Chromatography is used to find out if a banned dye, P, is present in foodstuffs.
The results are shown in the diagram.
Which foodstuff contains P?
20.
J. 2011 (2)
An aqueous solution is coloured. Which method of separation would show
that the solution contains ions of different colours?
A. chromatography
B. crystallisation
C. distillation
D. filtration
IGCSE
Grade (10)
21.
J. 2011 (3)
The table gives the solubility of four substances in ethanol and in water.
A mixture containing all four substances is added to ethanol, stirred and filtered.
The solid residue is added to water, stirred and filtered.
The filtrate is evaporated to dryness, leaving a white solid.
Which is the white solid?
22.
A mixture of ethanol and methanol are separated by fractional distillation.
N. 2011 (3)
This method of separation depends on a difference in property X of these two alcohols.
What is property X?
A. boiling point
B. colour
C. melting point
D. solubility
23.
J. 2012 (2)
Which method is most suitable to obtain zinc carbonate from a suspension of zinc
carbonate in water?
A. crystallisation
B. distillation
C. evaporation
D. filtration
IGCSE
24.
Grade (10)
J. 2012 (3)
A student investigates how the concentration of an acid affects the speed of reaction
with a 0.5 g mass of magnesium at 30 °C.
The student has a beaker, concentrated acid, water and the apparatus below.
P a balance
Q a clock
R a measuring cylinder
S a thermometer
Which pieces of apparatus does the student use?
A P, Q and R only
B P, Q and S only
C Q, R and S only
D P, Q, R and S
25.
N. 2012 (2)
A mixture of sulfur and iron filings needs to be separated. The solubilities of sulfur and
iron filings in water and carbon disulfide are shown in the table below.
What are possible methods of separating the sulfur and iron filings?
IGCSE
Grade (10)
26.
N. 2012 (3)
Part of the instructions in an experiment reads as follows.
Quickly add 50 cm3 of acid.
What is the best piece of apparatus to use?
A. a burette
B. a conical flask
C. a measuring cylinder
D. a pipette
IGCSE
Grade (10)
Paper 4
1.
J. 05 (5)
Enzymes are biological catalysts. They are used both in research laboratories and in
industry.
(a) Enzymes called proteases can hydrolyze proteins to amino acids. The amino acids can
be separated and identified by chromatography. The diagram below shows a typical
chromatogram
Some Rf values for amino acids are:
glutamic acid = 0.4 glycine = 0.5 alanine = 0.7 leucine = 0.9
Identify the two amino acids on the chromatogram.
A is…………………………….…..
B is …………………………….
[2]
IGCSE
Grade (10)
(ii) Explain why the chromatogram must be exposed to a locating agent before Rf
values can be measured.
………………………………………………………………………………………………………….[1]
(iii) Measuring Rf values is one way of identifying amino acids on a chromatogram.
Suggest another.
………………………………………………………………………………………………………….[1]
2.
N. 07 (1)
A list of techniques used to separate mixtures is given below.
Fractional
Distillation
simple
distillation
crystallization
filtration
diffusion
From the list choose the most suitable technique to separate the following.
water from aqueous copper(II) sulfate
……………………………………
helium from a mixture of helium and argon
……………………………………
copper(II) sulfate from aqueous copper(II) sulfate
……………………………………
ethanol from aqueous ethanol
……………………………………
barium sulfate from a mixture of water and barium sulfate………..…………………………
[5]
3.
J. 09 (1. a)
Some grass is crushed and mixed with the solvent, propanone. The colour pigments
are extracted to give a deep green solution.
(a)
(i) Draw a labelled diagram to describe how you could show that there is more
than one coloured pigment in the green solution.
IGCSE
Grade (10)
[3]
(ii) Given a pure sample of chlorophyll, how could you show that the green solution
from the grass contained chlorophyll?
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..[2]
IGCSE
Grade (10)
Paper 6
1.
J.02 (1.a,b)
The apparatus below was used to make carbon dioxide. Dilute hydrochloric acid was added
to calcium carbonate.
(a) Identify the pieces of apparatus labelled:
A .........................................................................................
B .........................................................................................
C .........................................................................................
[3]
(b) Indicate on the diagram with an arrow where the acid was added.
[1]
IGCSE
2.
The label shows the substances present in a bottle of lemon drink.
Grade (10)
J. 02
(2. b, c)
(a) A piece of litmus paper was dipped in the drink.
(i)
What colour will the paper turn?
..............................................................................................................................................[1]
(ii) Why does using litmus paper give a better result than adding Universal Indicator
solution to the drink?
.............................................................................................................................................
.............................................................................................................................................[1]
(b) How could a sample of pure water be obtained from the drink?
...........................................................................................................................................
...........................................................................................................................................
............................................................................................................................................[2]
(c) Describe an experiment you could carry out to show that the drink contained two
different yellow substances.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................[3]
IGCSE
3.
Grade (10)
J. 03
Look at the diagrams of common laboratory apparatus.
(1)
IGCSE
Grade (10)
(a) Complete the empty boxes to identify the pieces of apparatus labeled
[4]
(b) What name is given to the separation method in C?
...............................................................................................................................................[1]
(c) Which apparatus would be most suitable to obtain crystals from an aqueous solution of
copper(II) sulfate?
...............................................................................................................................................[1]
4.
N. 03
(1)
The apparatus below was used to separate ethanol from water.
(a) Complete the empty boxes to name the pieces of apparatus.
[3]
(b) Indicate by an arrow where heat is applied.
[1]
(c) Name this separation process.
................................................................................................................................................[2]
IGCSE
Grade (10)
5.
N. 03
(2)
A student extracted and investigated the orange colour in some sweets.
The student followed these instructions:
1 Collect sweets, a watch glass, a beaker, eye protection and 100 cm3 of ethanol.
2 Crush the sweets.
3 Place the crushed sweets in the beaker containing 100 cm3 of ethanol.
4 Boil the mixture with the watch glass covering the beaker.
5 Decant the liquid and concentrate it by evaporation until the colour is dark orange.
6 Investigate which colours are present in the orange solution.
(a) Why should the sweets be crushed?
..................................................................................................................................................
...............................................................................................................................................[2]
(b) Why should the experiment be carried out in a well-ventilated laboratory?
...............................................................................................................................................
…………………………………………………………………………………………………………[1]
(c) State one safety precaution that the student should have taken, other than carrying out
the experiment in a well-ventilated laboratory and using eye protection.
..............................................................................................................................................
………………………………………………………………………………………………………….[1]
(c) State the purpose of the watch glass.
.................................................................................................................................................[1]
(d) Explain the term decant.
.................................................................................................................................................[1]
IGCSE
Grade (10)
(f) Describe how the student could carry out instruction 6. You may draw a diagram in the
space below to help you answer the question.
.........................................................................................................................................
.........................................................................................................................................
.........................................................................................................................................
6.
N.04 (1.a,b)
The apparatus below was used to make hydrogen. Dilute hydrochloric acid was added to
zinc.
(a) Identify the pieces of apparatus labelled
A…………………………………………………………………………………………………………
B…………………………………………………………………………………………………………
[2]
(b) Complete the boxes
[1]
IGCSE
Grade (10)
7.
J. 05
(1.a,b)
A small piece of limestone was heated strongly and left to cool. A few drops of cold water
were added. The solid expanded and gave off steam.
(a) Complete the empty boxes to identify the pieces of apparatus labelled.
[3]
8.
(2)
J. 06
A sample of orange fruit jam was investigated to check the three colourings present.
Step 1 The jam was boiled with water.
Step 2 The mixture was filtered.
Step 3 The filtrate was concentrated.
Step 4 The concentrate was analysed by chromatography.
(a) What was the purpose of Step 1?
…………………………………………………………………………………………………………[1]
(b) Why was the mixture filtered?
………………………………………………………………………………………………………….[1]
(c) How was Step 3 carried out?
………………………………………………………………………………………………………….[1]
(d) Draw a diagram to show the possible paper chromatogram obtained in Step 4.
[2]
IGCSE
Grade (10)
9.
J. 07
(1)
A mixture of ethanol and water can be separated by fractional distillation. The apparatus
below can be used to carry out such a separation in the laboratory.
(a) Name each piece of apparatus.
A………………………………………………………………………………………………………
B………………………………………………………………………………………………………
C……………………………………………………………………….……………………..……. [3]
(b) What is the purpose of D?
………………………………………………………………………… ……………………..…….[1]
(c) How could the purity of the ethanol collected be checked?
……………………………………………………………………………………………………….[1]
IGCSE
Grade (10)
10.
J. 07 ((3)
Chromatography can be used to identify amino acids from a sample of protein.
The diagram shows the chromatogram obtained when four samples of amino acids were
analysed. The paper was sprayed with ninhydrin.
(a) Why is the origin line drawn in pencil?
…………………………………………………………………………………………………………[1]
(b) Which amino acids could possibly be the same?
…………………………………………………………………………………………………………[1]
(c) Which amino acid sample contains more than one amino acid? Explain your answer.
Sample…………………………………………………………………………………………………
Explanation……………………………………………………………………………………………
[2]
(d) Suggest why it is necessary to spray the chromatogram with ninhydrin.
…………………………………………………………….……………………………………………[1]
IGCSE
Grade (10)
Topic 3
Atoms, elements and
compounds
• Atomic structure
• Radioactive isotopes
• Electron distribution
• Ions and ionic bonds
• Molecules and covalent bonds
• Macromolecular (giant) structures
IGCSE
Grade (10)
Paper 2
1. The diagram shows the electronic structure of an atom
J. 02
What is the number of protons in the nucleus?
B. 3
C. 8
D. 13
A. 2
2. The diagrams show the structures of two forms, X and Y, of a solid element
What are suitable uses of X and Y, based on their structures?
(60)
J. 02 (8)
J. 09 (7)
IGCSE
Grade (10)
3. The diagrams show models of molecules.
J. 02 (11)
Which molecules could the above models represent?
4. The diagrams show the nuclei of four different atoms.
N. 02 (5)
Which two atoms are isotopes of each other?
A Q and R
5.
B Q and T
C R and S
D S and T
J. 03 (6)
What is the electronic structure of an atom with a proton number 5 and a nucleon
number 11?
A 1, 8, 2
B 2, 8, 1
6. What changes when an ion is made from an atom?
A the number of electrons only
B the number of neutrons only
C the number of protons only
D the number both of protons and of neutrons
C 2, 3
D 3, 2
J. 03 (7)
IGCSE
7. Strontium, Sr, is a metal that forms an ionic chloride SrCl2.
Sulfur, S, is a non-metal that forms a covalent chloride SCl2.
Grade (10)
J. 03 (8)
Which compound is likely to have the higher melting point (m.p.) and which is more soluble
in water?
8.
J.00 (8)
J.04 (8)
How many electrons are shared between the atoms in a molecule of methane, CH4, and in
a molecule of water, H2O?
9. In the diagrams, circles of different sizes represent atoms of different elements.
Which diagram can represent hydrogen chloride gas?
J.04 (7)
J.11 (6)
IGCSE
Grade (10)
10. The proton number of helium is 2.
J. 04 (11)
What information does this give about helium?
A Its atom has two electrons.
B Its atom is twice as heavy as a hydrogen atom.
C It is a Group II element.
D Its molecule has two atoms.
11. The diagrams show the arrangement of electrons in three different atoms.
J. 04 (22)
Which atoms are metals?
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3
12. Two isotopes of helium are 2He3 and 2He 4
J. 05
.Which two diagrams show the arrangement of particles in these two isotopes?
(4)
IGCSE
Grade (10)
13. The electronic configuration of an ion is 2.8.8.
What could this ion be?
14.
J. 05
J. 09
(6)
(6)
J. 05
Which statement about gaseous hydrogen chloride and solid potassium chloride is
correct?
(8)
A Hydrogen chloride is covalent but potassium chloride is ionic.
B Hydrogen chloride is ionic but potassium chloride is covalent.
C They are both covalent compounds.
D They are both ionic compounds.
15. Five elements have proton numbers 10, 12, 14, 16 and 18.
What are the proton numbers of the three elements that form oxides?
J. 06
(3)
A 10, 12 and 14
B 10, 14 and 18
C 12, 14 and 16
D 14, 16 and 18
16. The rows P, Q and R in the table show three pairs of structures.
J. 06 (4)
Which pair or pairs are isotopes?
A. P only
B. P and Q only
C. Q only
D. Q and R only
IGCSE
17.
Grade (10)
J. 06 (6)
In the molecules CH4, HCl and H2O, which atoms use all of their outer shell electrons in
bonding?
A. C and Cl
B. C and H
C. Cl and H
D. H and O
18. The table shows the nucleon numbers and proton numbers of some atoms.
How many are atoms of non-metallic elements?
A. 1
B. 2
C. 3
19. The table shows the electronic structures of four atoms.
Which two atoms combine to form an ionic compound?
A. W and X
B. W and Y
C. X and Y
20. The diagram shows the structure of methane.
A. 2
N.06 (5)
D. 4
N. 06 (6)
D. X and Z
J.07 (7)
What is the total number of electrons used for bonding in this molecule?
B. 4
C. 8
D. 10
IGCSE
Grade (10)
21. The diagram shows the structure of a substance.
J. 07
(8)
What is represented?
A. diamond
B. ethane
C. graphite
D. poly(ethene)
22. The table describes the structures of four particles.
What are the correct values of X, Y and Z?
N. 07 (7)
IGCSE
Grade (10)
23. The following statement is about chemical bonds.
N. 07 (8)
Covalent bonds are formed by the …1… of electrons. Covalent substances have …2…
electrical conductivity.
Which words complete the statement?
24. The electronic structures of atoms P and Q are shown.
J.08
(9)
P and Q react to form an ionic compound.
What is the formula of this compound?
A. PQ2
B. P2Q
C. P2Q6
D. P6Q2
IGCSE
Grade (10)
25. The diagram shows part of the Periodic Table.
N. 08 (6)
Which element is correctly matched with its electronic structure?
26. Which of the following compounds exist?
27. Which particle is an ion?
N.08 (7)
N. 08 (8)
IGCSE
Grade (10)
28. The diagram shows a molecule of hydrogen fluoride.
N. 08
(9)
In the molecule hydrogen fluoride, HF,
A.
B.
C.
D.
the hydrogen and fluorine share a pair of electrons.
the hydrogen and fluorine share a pair of protons.
the hydrogen gives the fluorine an electron.
the hydrogen gives fluorine a proton.
29. The diagram shows some properties that substances may have
J. 09 (15)
To which labelled part of the diagram does 235U belong?
30. The symbols of two atoms may be written as shown.
52
52
23 X
24 Y
J. 10
(6 )
Which statement about these atoms is correct?
A. They are different elements because they have different numbers of neutrons.
B. They are different elements because they have different numbers of protons.
C. They are isotopes of the same element because they have the same nucleon number.
D. They are isotopes of the same element because they have the same proton number.
IGCSE
Grade (10)
Paper 4
1.
J. 02 (4. c)
(c) Bromine reacts with phosphorus to form phosphorus tribromide.
Draw a diagram showing the arrangement of the valency electrons in one molecule of
this covalent compound. The electron distribution of bromine is:
2 + 8 + 18 + 7
Use x to represent an electron from phosphorus.
Use o to represent an electron from bromine.
2.
[3]
N. 02 (3. e)
(e) Draw a diagram that shows the arrangement of the valency electrons in the
ionic compound sodium phosphide.
Use o to represent an electron from sodium.
Use x to represent an electron from phosphorus.
3.
[3]
J. 03 (2. a)
(a) Boron is a non-metal with a macromolecular structure.
(iii) Name another element and a compound that have macromolecular structures.
element ……………………………..
compound ……………….…………
[2]
IGCSE
Grade (10)
(iv) Sketch the structure of one of the above macromolecular substances.
[2]
4.
J. 03 (5. a, d, e)
The first three elements in Period 6 of the Periodic Table of the Elements are caesium,
barium and lanthanum.
(a) How many more protons, electrons and neutrons are there in one atom of lanthanum
than in one atom of caesium. Use your copy of the Periodic Table of the Elements to
help you.
number of protons ...................................................
number of electrons ................................................
number of neutrons ................................................
[3]
(d) Barium chloride is an ionic compound. Draw a diagram that shows the formula of the
compound, the charges on the ions and gives the arrangement of the valency electrons
around the negative ion.
The electron distribution of a barium atom is 2 . 8 . 18 . 18 . 8 . 2
Use x to represent an electron from a barium atom.
Use o to represent an electron from a chlorine atom.
[2]
IGCSE
Grade (10)
(e) Describe, by means of a simple diagram, the lattice structure of an ionic compound,
such as caesium chloride.
[2]
5.
J. 04 (1. b)
(b) Silicon has the same type of macromolecular structure as diamond.
(i) Explain why one atom of either element can form four covalent bonds.
………………………………………………………………………………………………………...
………………………………………………………………………………………………………...[2]
(ii) Predict two physical properties of silicon.
………………………………………………………………………………………………………..
…………………………………………………………………………………………….………..[2]
(iii) Name a different element that has a similar structure and properties to silicon.
………………………………………………………………………………………………..[1]
6.
J. 04 (3. b)
(b) Draw a diagram to show the arrangement of the valency electrons in one molecule of
nitrogen.
[2]
IGCSE
7.
Grade (10)
N. 04 (5. b, c)
(b) Draw a diagram showing the arrangement of the valency electrons in one covalent
molecule of sulfur chloride.
Use x to represent an electron from a sulfur atom.
Use o to represent an electron from a chlorine atom.
[3]
(c) Explain the difference in electrical conductivity between the following.
(i) solid and liquid strontium chloride
……………………………………………………………………………………………………
…………………………………………………………………………………………………… [1]
(ii) liquid strontium chloride and liquid sulfur chloride
……………………………………………………………………………………………………
…………………………………………………………………………………………………… [1]
8.
J.05 (4. b)
(iii) Draw a diagram to show the arrangement of the valency electrons in one molecule
of the covalent compound hydrogen sulfide.
Use o to represent an electron from a sulfur atom.
Use x to represent an electron from a hydrogen atom.
IGCSE
Grade (10)
[2]
9.
N. 05 (1)
(a) The structure of a typical ionic compound is a regular arrangement of positive and
negative ions.
(i) What is the name of this regular arrangement of particles?
………………………………………………………………………………………………… [1]
(ii)Give two physical properties of ionic compounds.
……………………………………………………………………………………………………
…………………………………………………………………………………………………….[2]
(b) Ions are formed by electron loss or gain. The electron distribution of a magnesium
atom is 2 + 8 + 2 and of a nitrogen atom is 2 + 5.
(i)
Give the formula of the magnesium ion.
……………………………………………………………………………………………………….[1]
(ii)
Give the formula of the nitride ion.
………………………………………………..……………………………………………………..[1]
(iii) What is the formula of the ionic compound, magnesium nitride?
……………………………………………………………….………………………………………[1]
(iv) In this compound there is an ionic bond. Why are the two ions attracted to each other?
………………………………………………………………………………………………………..[1]
IGCSE
10.
Grade (10)
N. 05 (5. a)
Strontium and zinc are both metals with a valency of 2. Strontium is more reactive than
zinc. Its chemistry is similar to that of calcium.
(a) (i) Complete the following table that shows the number of protons, electrons and
neutrons in each particle.
(ii)Explain why 88Sr and 90Sr are isotopes.
…………………………………………………………………………………………………….[1]
(iv) Complete the electron distribution of an atom of strontium.
2 + 8 + 18 + …… … + ……....
11.
[1]
J. 06 (4)
The first three elements in Group IV are
carbon,
silicon,
germanium.
(a) The element germanium has a diamond-type structure. Describe the structure of
germanium. A diagram is acceptable.
……………………………………………………………………………………………………..
……………………………………………………………………………………………………….[2]
(b) Unlike diamond, graphite is soft and is a good conductor of electricity.
(i) Explain why graphite has these properties.
……………………………………………………………………………………………………
……………………………………………………………………………………………………
………………………………………………………………………………………………..…[3]
IGCSE
Grade (10)
(ii) Give a use of graphite that depends on one of these properties.
Property…………………………………………………………………………………………
Use
………………………………………………………………………………………. [1]
(c) Carbon dioxide and silicon(IV) oxide have similar formulae but different types of
structure.
(i) Give the formulae of these oxides.
……………………………………………………………………………………………………[1]
(ii) How are their structures different?
…………………………………………………………………………………………………..
…………………………………………………………………………………………………….[2]
12.
(b) Some radioactive isotopes are used as nuclear fuels.
J. 06 (6. b)
(i) Give the symbol and the nucleon number of an isotope that is used as a nuclear
fuel.
………………………………………………………………………………………………….
…………………………………………………………………………………………………..[2]
(ii) Give another use of radioactive isotopes.
………………………………………………………………………………………………….[1]
IGCSE
Grade (10)
13.
The table shows the melting points, boiling points and electrical properties of
the six substances A to F.
N. 06 (2)
(i)
Which three substances are solids at room temperature?
……………………………………………………………………………………………………….[1]
(ii)
Which one is an ionic compound?
……………………………………………………………………………………………………….[1]
(iii) Which one is a gas at room temperature?
……………………………………………………………………………………………………….[1]
(iv) Which two substances are liquids at room temperature?
………………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
14.
(d) Give a diagram showing the arrangement of the valency electrons in one
molecule of the covalent compound urea.
06 (5. d)
Its structural formula is given below.
Use ο to represent an electron from a carbon atom.
Use x to represent an electron from a hydrogen atom.
Use • to represent an electron from a nitrogen atom.
15.
Complete the following table.
J. 07 (2)
IGCSE
Grade (10)
16.
J. 07 (4. c)
(c) Draw a diagram showing the arrangement of the valency electrons in one
molecule of
the covalent compound nitrogen trichloride.
Use x to represent an electron from a nitrogen atom.
Use o to represent an electron from a chlorine atom.
[3]
17.
N. 07 (2. a, b)
The table below gives the number of protons, neutrons and electrons in atoms
or ions.
(a) Complete the table. The first line is given as an example.
[6]
(b) Which atom in the table is an isotope of the atom which has the composition
11p, 11e and 14n?
Give a reason for your choice.
………………………………………………………………………………………………………..
………………………………………………………………………………………………………..
[2]
IGCSE
Grade (10)
18.
Magnesium reacts with bromine to form magnesium bromide.
N. 07 (3. a, b)
(a) Magnesium bromide is an ionic compound. Draw a diagram that shows the formula
of the compound, the charges on the ions and the arrangement of outer
electrons around the negative ion.
The electron distribution of a bromine atom is 2, 8, 18, 7.
Use x to represent an electron from a magnesium atom.
Use o to represent an electron from a bromine atom.
[3]
(b) In the lattice of magnesium bromide, the ratio of magnesium ions to bromide ions is1:2.
(i) Explain the term lattice.
……………………..……………………………………………………………………………….
……………….……………………………………………………………………………………[2]
(iii) Explain why the ratio of ions is 1:2.
……………………………………………………………………………………………………[1]
19.
J. 08 (2)
(a) Complete the table which gives the names, symbols, relative masses and
relative charges of the three subatomic particles.
IGCSE
Grade (10)
(b) Use the information in the table to explain the following.
(i) Atoms contain charged particles but they are electrically neutral because
they have no overall charge.
…………………………………………………………………………………………………
.……………………………………………………………………………………………….. [2]
(ii) Atoms can form positive ions.
……………………………………………………………………………………………………….
.. …………………………………………………………………………………………………..[2]
(iii) Atoms of the same element can have different masses.
…. …………………………………………………………………………………………………
……………………………………………………………………………………………………[2]
(iv) Scientists are certain that there are no undiscovered elements missing from
the Periodic Table from hydrogen to lawrencium
………………………………………………………………………………………………………[1]
20.
(d) The structural formula of carbonyl chloride is given below.
Draw a diagram that shows the arrangement of the valency electrons in one
molecule of this covalent compound.
Use x for an electron from a chlorine atom.
Use o for an electron from a carbon atom.
Use ● for an electron from an oxygen atom.
J. 08 (5. d)
IGCSE
Grade (10)
21.
N. 08 (2. a,
There are three types of giant structure – ionic, metallic and macromolecular.
c)
(a) Sodium sulfide is an ionic compound. Draw a diagram that shows the formula of the
compound, the charges on the ions and the arrangement of the valency electrons
around the negative ion.
Use x to represent an electron from a sodium atom.
Use o to represent an electron from a sulfur atom.
(c)
Silicon(IV) oxide has a macromolecular structure.
(i) Describe the structure of silicon(IV) oxide (a diagram is not acceptable).
…………………………………………………………………………………………………...
…………………………………………………………………………………………………..[3]
(ii) Diamond has a similar structure and consequently similar properties.
Give two physical properties common to both diamond and silicon(IV) oxide.
……………………………………………………………………………………………….
……………………………………………………………………………………………….[2]
IGCSE
Grade (10)
Topic 4
Stoichiometry
• Chemical formula
• Chemical equation
• Chemical calculations
• The mole
• Empirical formula and molecular
formula
IGCSE
Grade (10)
Paper 2
1. Which compound has the largest relative molecular mass, Mr?
A. CO2
B. NO2
C. SiO2
D. SO2
J. 02
(9)
2. What is the formula of copper(II) oxide and of sulfur hexafluoride?
J. 02 (10)
3. The relative atomic mass of oxygen is 16 and that of hydrogen is 1.
J. 03 (9)
This means that …(i)… of oxygen has the same mass as …(ii)… of hydrogen.
Which words correctly complete the gaps?
4. Water is formed when 48 g of oxygen combine with 6 g of hydrogen.
J. 03 (11)
What mass of oxygen combines with 2 g of hydrogen?
A. 12 g
B. 16 g
C. 96 g
D. 144 g
IGCSE
Grade (10)
5. Two gases react as shown.
N. 03 (10)
When measured at the same temperature and pressure, what is the value of
A. 1/2
B. 1
C. 2
D. 4
6. Carbon and chlorine form a chloride.
N. 03 (11)
N. 08 (11)
What is the formula of this chloride?
A. CCl2
B. CCl4
C. CaCl2
D. CaCl4
7. The compound ethyl mercaptan, C2H5SH, has a very unpleasant smell.
J. 04
(10)
What is its relative molecular mass?
A. 34
B. 50
C. 61
D. 62
8. When propane is burned, carbon dioxide and water are formed, as shown.
C3H8 + 5O2
r CO2 + s H2O
Which values of r and s balance the equation?
N. 04 (9)
IGCSE
Grade (10)
9. For which compound is the formula correct?
J 05 (10)
10. The equation shows the reaction that occurs when ethanol burns in air.
N. 05 (9)
C2H5OH + x O2 →
y CO2 + z H2O
Which values of x, y and z are needed to balance this equation?
11. The diagrams show the molecules of three elements.
Which of these elements are present in water?
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
J. 06 (9)
IGCSE
12. Magnesium and sulfur each form a chloride.
Grade (10)
N 06
(9)
What could be the formulae of these chlorides?
13. A gas has the molecular formula NOCl.
Which diagram could show molecules of the pure gas NOCl ?
N. 06 (10)
IGCSE
Grade (10)
14. Boron, B, forms an oxide.
J. 07 (10)
Which equation is correctly balanced?
A. 2B + 3O2 → B2O3
B. 2B + 3O2 → 2B2O3
2B2O3
C. 4B + 2O2 →
D. 4B + 3O2 → 2B2O3
15. For which compound is the formula correct?
J. 08 (10)
16.
J. 08 (18)
When written as formulae, which compound has the greatest number of oxygen atoms?
A. calcium oxide
B. copper(II) oxide
C. iron(III) oxide
D. potassium oxide
17. Nitrogen and hydrogen react together to form ammonia.
N2 + 3H2 →
J. 09 (10)
2NH3
When completely converted, 7 tonnes of nitrogen gives 8.5 tonnes of ammonia.
How much nitrogen will be needed to produce 34 tonnes of ammonia?
A 7 tonnes
B 8.5 tonnes
C 28 tonnes
D 34 tonnes
IGCSE
Grade (10)
18. Which relative molecular mass, Mr, is not correct for the molecule given?
J. 09 (11)
19. Hydrogen and chlorine react as shown.
1 molecule of hydrogen + 1 molecule of chlorine → 2 molecules of hydrogen chloride
What is the equation for this reaction?
A. 2H + 2Cl → 2HCl
B. 2H + 2Cl → H2Cl 2
C. H2 + Cl 2 → 2HCl
D. H2 + Cl 2 → H2Cl 2
IGCSE
Grade (10)
Paper 4
1.
N. 01 (2. c)
(c) Potassium chlorate, which has a formula of the type, KClOn, decomposes to form
oxygen. 2.45 g of the chlorate produced 1.49 g of potassium chloride and 0.72dm3 of
oxygen at r.t.p. Find the value of n.
KClOn
KCl
+ O2
Mass of one mole of KCl = 74.5 g
Number of moles of KCl formed = .................................................................................
Number of moles of oxygen molecules formed = ..........................................................
Number of moles of oxygen atoms = .............................................................................
Mole ratio KCl : O is ......................................................................................................
n = ..............................
[4]
2.
N. 01 (3. a)
Propane is an alkane. It has the structural formula:
(a) The equation for the complete combustion of propane is given below. Insert the two
missing volumes.
Volume of gas/cm3
C3H8(g) +
5O2(g)
........
.......
3CO2(g) + 4H2O(l)
15
IGCSE
Grade (10)
3.
J. 02 (5. c, d)
3
3
(c) A 20 cm sample of butyne, C4H6, is burnt in 150 cm of oxygen. This is an excess of
oxygen.
2C4H6(g) + 11O2(g)
(i)
8CO2(g) + 6H2O(l)
What volume of oxygen reacts?
……….................................................................................................................................[1]
(ii) What volume of carbon dioxide is produced?
……….................................................................................................................................[1]
(iii) What is the total volume of gases left at the end of the reaction?
……….................................................................................................................................[1]
(d) Calculate the mass of water formed when 9.0 g of butyne is burnt. The mass of one
mole of butyne is 54 g.
from the above equation, 1 mole of butyne forms 3 moles of water
number of moles of butyne reacted ...............
number of moles of water formed .................
mass of water formed ............... g
[3]
4.
N. 02 (1. c)
(c) The results of an investigation into the action of heat on copper(II) sulphate-5-water, a
blue crystalline solid, are given below.
The formula is CuSO4.5H2O and the mass of one mole is 250 g
A 5.0 g sample of the blue crystals is heated to form 3.2 g of a white powder. With
further heating this decomposes into a black powder and sulfur trioxide.
(i) Name the white powder.
.............................................................................................................................................[1]
IGCSE
Grade (10)
(ii) What is observed when water is added to the white powder?
.............................................................................................................................................[1]
(iii)Name the black powder.
.............................................................................................................................................[1]
(iv) Calculate the mass of the black powder. Show your working.
..............................................................................................................................................
..............................................................................................................................................
.............................................................................................................................................[3]
4.
N. 02 (3. f)
(f) Sodium reacts with sulfur to form sodium sulfide.
2Na
+
S
Na2S
An 11.5 g sample of sodium is reacted with 10 g of sulfur. All of the sodium reacted but
there was an excess of sulfur.
Calculate the mass of sulfur left unreacted.
(i) Number of moles of sodium atoms reacted = ...............................................................
[2 moles of Na react with 1 mole of S]
(ii) Number of moles of sulfur atoms that reacted = ...........................................................
(iii) Mass of sulfur reacted = ..............................................................g
(iv) Mass of sulfur left unreacted = ...................................................g
[4]
IGCSE
Grade (10)
5.
J. 03 (2. c)
(c) Each tablet contains the same number of moles of CaCO3 and MgCO3. One tablet
reacted with excess hydrochloric acid to produce 0.24 dm3 of carbon dioxide at r.t.p.
CaCO3 + 2HC l
CaCl2
+ CO2 + H2O
MgCO3 + 2HCl
MgCl2
+ CO2 + H2O
(i) Calculate how many moles of CaCO3 there are in one tablet.
number of moles CO2 = ......................................................................................................
number of moles of CaCO3 and MgCO3 = .........................................................................
number of moles of CaCO3 = .............................................................................................
[3]
(ii) Calculate the volume of hydrochloric acid, 1.0 mol /dm3, needed to react with one
tablet.
number of moles of CaCO3 and MgCO3 in one tablet = ......................................................
Use your answer to (c)(i).
number of moles of HCl needed to react with one tablet = ..................................................
volume of hydrochloric acid, 1.0 mol /dm3, needed to
react with one tablet = ..........................................................................................................
[2]
6.
N. 03 (5. d)
(d) Sulfur dioxide reacts with chlorine in an addition reaction to form sulfuryl chloride.
SO2 + Cl2
SO2Cl2
8.0 g of sulfur dioxide was mixed with 14.2 g of chlorine. The mass of one mole of
SO2Cl2 is 135 g.
Calculate the mass of sulfuryl chloride formed by this mixture.
Calculate the number of moles of SO2 in the mixture = ………………………………………
Calculate the number of moles of Cl2 in the mixture = ……………………………..…………
IGCSE
Grade (10)
Which reagent was not in excess? …………………………………………………………….
How many moles of SO2Cl2 were formed = …………………………………….…………….
Calculate the mass of sulfuryl chloride formed = ………………….……. g
7.
[5]
J. 04 (3. a)
An organic compound decomposes to form nitrogen.
C6H5N2Cl(aq)
→
C6H5Cl(l)
+
N2(g)
(a) Explain the state symbols.
aq……………………..
l ……………………..
g …………………….
8.
[2]
J. 04 (7)
Chemists use the concept of the mole to calculate the amounts of chemicals involved in a
reaction.
(a) Define mole.
………………………………………………………………………………………………………[1]
(b) 3.0 g of magnesium was added to 12.0 g of ethanoic acid.
Mg
+
2CH3COOH
→
(CH3COO)2Mg
+
H2
The mass of one mole of Mg is 24 g.
The mass of one mole of CH3COOH is 60 g.
(i) Which one, magnesium or ethanoic acid, is in excess? You must show your
reasoning.
.............................……………………………………………………..…………………………
…………………………………………………………………………..………………………….
…………………………………………………………………………………………………….[3]
IGCSE
Grade (10)
(ii) How many moles of hydrogen were formed?
……………………………………………………………………………………………………..[1]
(iii) Calculate the volume of hydrogen formed, measured at r.t.p
……………………………………………………………………………..…………………………
………………………………………………………………………………………………………[2]
(c) In an experiment, 25.0cm3 of aqueous sodium hydroxide, 0.4mol /dm3 was neutralised
by 20.0cm3 of aqueous oxalic acid, H2C2O4.
2NaOH
+
H2C2O4
→
Na2C2O4
+
2H2O
Calculate the concentration of the oxalic acid in mol /dm3
(i) Calculate the number of moles of NaOH in 25.0 cm3 of 0.4 mol /dm3 solution.
…………………………………………………………………………………………………… [1]
(ii) Use your answer to (i) and the mole ratio in the equation to find out the number of
moles of H2C2O4 in 20 cm3 of solution.
…………………………………………………………………………………………………….. [1]
(ii) Calculate the concentration, mol /dm3, of the aqueous oxalic acid.
………………………………………………………………………………………………………
……………………………………………………………………………………………………… [2]
IGCSE
9.
Grade (10)
N. 04 (7. c)
(c) Iron(III) sulfate decomposes when heated. Calculate the mass of iron(III) oxide
formed and the volume of sulfur trioxide produced when 10.0 g of iron(III) sulfate
was heated.
Mass of one mole of Fe2(SO4)3 is 400 g.
Fe2(SO4)3 (s)
Fe2O3 (s)
+
3SO3 (g)
Number of moles of Fe2(SO4)3 = ………………………………………………
Number of moles of Fe2O3 formed = …………………………………………..
Mass of iron(III) oxide formed = ……………………………………………..
g
Number of moles of SO3 produced = ………………………………………
Volume of sulfur trioxide at r.t.p. =
………………………………………..
dm3
[5]
10.
J. 05 (1. c, d)
(c) 0.015 moles of iodine react with 0.045 moles of chlorine to form 0.030 moles of a single
product. Complete the equation.
I2
+ ……….. Cl2
…………………………….
[2]
(d) Traces of chlorine can be separated from bromine vapour by diffusion.
Which gas would diffuse the faster and why?
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
11.
J. 05 (4. d)
(d) Gypsum is hydrated calcium sulfate, CaSO4.xH2O. It contains 20.9% water by mass.
Calculate x.
Mr: CaSO4, 136;
H2O, 18.
79.1 g of CaSO4 = ………………………………………………………………………moles
20.9 g of H2O = ……………………………………………………………………….… moles
x = ………………..
[3]
IGCSE
Grade (10)
12.
(a) The following method is used to make crystals of hydrated nickel sulfate.
N. 05 (6. a)
An excess of nickel carbonate, 12.0 g, was added to 40 cm3 of sulfuric acid, 2.0
mol/dm3. The unreacted nickel carbonate was filtered off and the filtrate evaporated to
obtain the crystals.
NiCO3
+
H2SO4
NiSO4 + CO2 + H2O
NiSO4
+
7H2O
NiSO4.7H2O
Mass of one mole of NiSO4.7H2O = 281 g
Mass of one mole of NiCO3 = 119 g
(i) Calculate the mass of unreacted nickel carbonate.
Number of moles of H2SO4 in 40 cm3 of 2.0 mol/dm3 acid = 0.08
Number of moles of NiCO3 reacted =………………………………………………………
Mass of nickel carbonate reacted =………………………………………………………. g
Mass of unreacted nickel carbonate = ………………………………………………….. g [3]
(ii) The experiment produced 10.4 g of hydrated nickel sulfate. Calculate the
percentage yield.
The maximum number of moles of NiSO4 .7H2O that could be formed =…………………
The maximum mass of NiSO4 .7H2O that could be formed =…………………………….. g
The percentage yield =……………………………………………………. %
[3]
IGCSE
Grade (10)
13.
(d) Propene reacts with hydrogen iodide to form 2 - iodopropane.
J. 06 (7. d)
CH3−CH=CH2
+
HI
CH3−CHI−CH3
1.4 g of propene produced 4.0 g of 2 - iodopropane.
Calculate the percentage yield.
moles of CH3–CH=CH2 reacted = ………………………………………………………………
maximum moles of CH3–CHI–CH3 that could be formed =…………………………………..
mass of one mole of CH3–CHI–CH3 = 170 g
maximum mass of 2 - iodopropane that could be formed =…………………………………
percentage yield ……………………………………………..%
14.
(b) When calcium carbonate is heated strongly, it decomposes.
CaCO3
→
CaO
+
[4]
N. 06 (3. b)
CO2
(i) Calculate the relative formula mass of:
CaCO3 ……………………………………………………………………………………………
CaO …….…………………………………………………………………………………… [2]
(ii) 7.00 kg of calcium oxide was formed. What mass of calcium carbonate was heated?
………………………………………………………………………………………………………..
…… …………………………………………………………………………………….…………[2]
IGCSE
Grade (10)
15.
N. 06 (6. a)
An ore of copper is the mineral, chalcopyrite. This is a mixed sulfide of iron and copper.
(a) Analysis of a sample of this ore shows that 13.80 g of the ore contained
4.80g of copper, 4.20 g of iron and the rest sulfur.
Complete the table and calculate the empirical formula of chalcopyrite.
[3]
The empirical formula is…………………………………………………………………
[1]
16.
J. 07 (7. d)
(d) A better way of measuring the degree of unsaturation is to find the iodine number
of the unsaturated compound.
This is the mass of iodine that reacts with all the double bonds in 100 g of the fat.
Use the following information to calculate the number of double bonds in one
molecule of the fat.
Mass of one mole of the fat is 884 g.
One mole of I2 reacts with one mole
The iodine number of the fat is 86.2 g.
Complete the following calculation.
100 g of fat reacts with 86.2 g of iodine.
884 g of fat reacts with ………………………………………………………..….g of iodine.
IGCSE
Grade (10)
One mole of fat reacts with…………………………………….. moles of iodine molecules.
Number of double bonds in one molecule of fat is………………………………………….. [3]
17.
(ii) One piece of marble, 0.3 g, was added to 5 cm3 of hydrochloric acid,
concentration 1.00 mol / dm3.
N. 07 (7. b)
Which reagent is in excess? Give a reason for your choice.
mass of one mole of CaCO3 = 100 g
number of moles of CaCO3 =……………………………………………………………………
number of moles of HCl =……………………………………………………………………….
reagent in excess is……………………………………………………………………………..
reason…………………………………………………………………………………………..…
.....………………………………………………………………………………..………………. [4]
(iii) Use your answer to (ii) to calculate the maximum volume of carbon dioxide
produced measured at r.t.p.
… ………………………………………………………………………………………………….[1]
18.
J. 08 (7. b)
(b) Using 25.0 cm3 of aqueous sodium hydroxide, 2.24 mol / dm3, 3.95 g of
crystals were obtained. Calculate the percentage yield.
2NaOH
Na2SO4
+
H2SO4
Na2SO4
+ 2H2O
+ 10H2O
Na2SO4.10H2O
Number of moles of NaOH used =……………………………………………………………………
Maximum number of moles of Na2SO4.10H2O that could be formed =………………………….
Mass of one mole of Na2SO4.10H2O = 322 g
Maximum yield of sodium sulphate-10-water =………………………………….………………… g
Percentage yield =………………………………………………………………………..…. %
[4]
IGCSE
Grade (10)
19.
(c) (i) Calculate the mass of one mole of Fe2O3.2H2O.
N. 08 (3. c)
………………………………………………………………………………………………………[1]
(ii) Use your answer to (i) to calculate the percentage of iron in rust.
……………………………………………………………………………………………………..
……………………………………………………………………………………………………..[2]
20.
N. 08 (4. b)
(b) Benzene contains 92.3% of carbon and its relative molecular mass is 78.
(i) What is the percentage of hydrogen in benzene?
…………………………………………………………………………………………………….[1]
(ii)
Calculate the ratio of moles of C atoms: moles of H atoms in benzene.
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
(iii) Calculate its empirical formula and then its molecular formula.
The empirical formula of benzene is……………………………………………………….
The molecular formula of benzene is……………………………………………………..
……………………………………………………………………………………………….. [2]
IGCSE
21.
Grade (10)
N. 08 (7. a)
alkanes are generally unreactive. Their reactions include combustion, substitution and
cracking.
(a) The complete combustion of an alkane gives carbon dioxide and water.
(i) 10 cm3 of butane is mixed with 100 cm3 of oxygen, which is an excess. The mixture
is ignited. What is the volume of unreacted oxygen left and what is the volume of
carbon dioxide formed?
C4H10(g) +
6.5 O2 (g)
4CO2(g) +
5H2O(l)
Volume of oxygen left = ……………………………………………………cm3
Volume of carbon dioxide formed = ………………………………….…..cm3
[2]
IGCSE
Grade (10)
22.
J. 09 (5. b)
(b) The formulae of insoluble compounds can be found by precipitation reactions.
To 12.0 cm3 of an aqueous solution of the nitrate of metal T was added 2.0 cm3
of aqueous sodium phosphate, Na3PO4. The concentration of both solutions was
1.0 mol / dm3. When the precipitate had settled, its height was measured.
The experiment was repeated using different volumes of the phosphate solution. The
results are shown on the following graph.
What is the formula of the phosphate of metal T ? Give your reasoning.
………………………………………………………………………………………………….
………………………………………………………………………………………………….
……………………………………………………………………………………………….. [3]
IGCSE
Grade (10)
23.
J. 09 (9)
Quantities of chemicals, expressed in moles, can be used to find the formula of
a compound, to establish an equation and to determine reacting masses.
(a) A compound contains 72% magnesium and 28% nitrogen. What is its empirical
formula?
………………………………………………………………………………………………………
………………………………………………………………………………………………..……[2]
(b) A compound contains only aluminium and carbon. 0.03 moles of this compound
reacted with excess water to form 0.12 moles of Al(OH)3 and 0.09 moles of CH4
Write a balanced equation for this reaction.
…………………………………………………………………………………………….………
…………………………………………………………………………………………………...[2]
(c) 0.07 moles of silicon reacts with 7.2 g of fluorine.
Si
(i)
+
2F2
SiF4
Which one is the limiting reagent? Explain your choice.
….………………………………………………………………………………………………..
… ………………………………………………………………………………………………[3]
(ii)
How many moles of SiF4 are formed?
…………………………………………………………………………………..……………[1]
IGCSE
Grade (10)
Topic 5
The periodic table
• Trend in group I (The alkali metals)
• Transition metals
• Trend in group VII (The halogens)
• Nobel gases
• Test and collection of gases
• Oxidation and reduction
IGCSE
Grade (10)
Paper 2
1. Zinc reacts with steam to form zinc oxide and hydrogen.
Zn + H2O
J. 02 (18)
ZnO + H2
During the reaction, which substance is oxidised?
A.
B.
C.
D.
hydrogen
water
zinc
zinc oxide
2. The proton numbers of four elements are shown.
J 02 (23)
Which element is a metal?
3. Which properties does a transition element have?
N 02 (17)
IGCSE
Grade (10)
4.
N 02 (22)
Which statement about the electrical conductivity of non-metals and the charge on their
ions is correct?
5.
N 02 (24)
A few drops of aqueous bromine are added to separate aqueous solutions of potassium
chloride, potassium bromide and potassium iodide.
Which solutions do not remove the colour of the bromine?
A. KBr and KCl only
B. KBr and KI only
C. KCl and KI only
D. KBr, KCl and KI
6.
J.03 (15)
When hydrogen is passed over a heated metal oxide, the metal and steam are formed.
What happens to the hydrogen and to the metal oxide?
IGCSE
7. Which test method and gas are correctly linked?
8. An inert gas X is used to fill weather balloons.
Grade (10)
J 03 (20)
J. 03 (23)
Which descriptions of X are correct?
9. A student is asked to complete two sentences.
J.03 (24) / J. 06 (22)
Metallic and non-metallic elements are classified in the …(i)… This can be used to …(ii)…
the properties of elements
.
Which words correctly complete the gaps?
IGCSE
Grade (10)
10. Which element is a solid non-metal?
N. 03 (8)
11. Lead(II) oxide is reduced in the apparatus shown.
How do the masses of parts X and Y of the apparatus change?
IGCSE
Grade (10)
12. Vanadium is a transition metal.
What are its likely properties?
N. 03 (23)
13. The table gives information about four elements.
N. 03 (24)
Which element could be in Group I in the Periodic Table?
14. Which properties does a Group VI element have?
J. 04 (5)
IGCSE
15.
Grade (10)
J. 04 (16) / N. 07 (25)
In an experiment, copper(II) oxide is changed to copper by a gas X.
What happens to the copper(II) oxide and what is X?
16. Metals can be joined together by welding them at a high temperature.
N. 04 (22)
Why is an argon atmosphere often used?
A.
B.
C.
D.
Argon has a low density.
Argon is colourless.
Argon is inexpensive.
Argon is unreactive.
17. In which reaction does reduction of the underlined substance take place?
2Cu + CO
A. Cu2O + C
B. 2Cu2O + O2
4CuO
C. 2Cu
+ O2
2CuO
D. CuO
+ CO
Cu + CO2
N. 04
18. The diagram shows part of the Periodic Table.
N. 04 (24)
Which statement about elements X, Y and Z is correct?
The proton number of X is
A. seven less than that of Z.
B. three less than that of Z.
C. one less than that of Y.
D. sixteen less than that of Y
(17)
IGCSE
Grade (10)
19. Which substance is a metal?
N. 04 (26)
20. What is the colour of liquid bromine and of the aqueous bromide ion?
J. 05 (18)
21. The chemical properties of an element depend mainly on the number of
J. 05 (23)
A.
B.
C.
D.
electrons in the innermost shell.
electrons in the outermost shell.
fully occupied shells of electrons.
partly occupied shells of electrons.
22. An element X is in Group III of the Periodic Table.
Which property of X can be predicted from this fact?
A.
B.
C.
D.
the charge on an ion of X
the colour of the ion of X
the melting point of X
the relative atomic mass, Ar, of X
J. 05 (24)
IGCSE
Grade (10)
23.
J. 05 (25)
The table compares the properties of Group I elements with those of transition elements.
Which entry in the table is correct?
24. Cesium is near the bottom of Group I of the Periodic Table.
What is the correct description of cesium?
J. 05 (26)
25.
N. 05 (21)
Which information about an element can be used to predict its chemical properties?
A. colour of its compounds
B. density
C. melting point
D. position in the Periodic Table
26. The table shows some properties of four gases.
Which gas is most suitable for filling weather balloons?
N. 05
(23)
IGCSE
Grade (10)
27. A data book gives the following information about an element.
N. 05 (23)
Where is the element likely to be found in the Periodic Table?
A. Group 0
B. Group I
C. Group VII
D. transition elements
28.
N. 05 (24)
Calcium, on the left of Period 3 of the Periodic Table, is more metallic than bromine on the
right of this Period. Why is this?
Calcium has
A. fewer electrons.
B. fewer protons.
C. fewer full shells of electrons.
D. fewer outer shell electrons.
29. The diagram shows the positions of some elements in the Periodic Table.
Which elements form ionic bonds with oxygen?
A. W only
B. W and X only
C. Y only
D. Y and Z only
J. 06 (20)
IGCSE
30.
Grade (10)
J. 06 (20)
The equation shows the reaction between a halogen and aqueous bromide ions.
X2 + 2Br–(aq)
→
2X–(aq) + Br2
…1… …2…
…3…
Which words should be written in gaps 1, 2 and 3?
31. The diagram shows an outline of part of the Periodic Table.
J. 06
Which two elements could form a covalent compound?
A. W and X
B. W and Y
C. X and Y
D. X and Z
32. The diagram shows three balloons held by children.
J. 06
Which of the balloons float up into the air when the children let go?
A. P only
B. P and R only
C. Q only
D. Q and R only
(21)
(23)
IGCSE
Grade (10)
33. Which equation shows an oxidation reaction?
A.
B.
C.
D.
N. 06
(16)
N. 06
(20)
C + O2 → CO2
CaCO 3 → CaO + CO2
2H2O2
→ 2H2O + O2
N2O4
→ 2NO2
34. Which piece of equipment can be used to show that a gas is hydrogen?
35.
J. 06 23)
An element does not conduct electricity but it does exist as diatomic molecules.
In which area of the Periodic Table is the element to be found?
IGCSE
Grade (10)
36. Which properties of helium explain its use in filling balloons?
N. 06 (24)
37.
J. 07 (6)
Element Y is in the second Period of the Periodic Table. An atom of element Z has six
more protons than an atom of element Y.
Which statement must be correct?
A.
B.
C.
D.
38.
Elements Y and Z are in the same Period.
Elements Y and Z have the same number of electrons in the first shell.
Element Z has six more electrons in its outer shell than element Y.
The nucleon number of element Z is six more than that of element Y.
Three reactions used in the manufacture of sulfuric acid are shown.
1. S + O2
→ SO2
2. 2SO2 + O2 → 2SO3
3. SO3 + H2O → H2SO4
Which of these reactions are redox reactions?
A. 1 only
B. 3 only
C. 1 and 2 only
D. 2 and 3 only
39. The diagram shows an outline of part of the Periodic Table.
J. 07
(16)
J. 07 (23)
Which two elements could form a covalent compound?
A. W and X
B. W and Y
C. X and Y
D. X and Z
IGCSE
Grade (10)
40. Which substances react with aqueous potassium bromide to form bromine?
J. 07 (25)
41. Why are some weather balloons filled with helium rather than hydrogen?
A. Helium is found in air.
B. Helium is less dense than hydrogen.
C. Helium is more dense than hydrogen.
D. Helium is unreactive.
J. 07 (25)
42. The table shows the densities of some Group I metals.
J. 07 (26)
3
Which of these metals sinks in benzene (density = 0.88 g / cm ) but floats in nitrobenzene
(density = 1.2 g / cm3)?
43. Rubidium is below potassium in Group I of the Periodic Table.
• The melting point of rubidium is …...1…... than that of potassium.
• The reaction of rubidium with water is ……2…… than that of potassium.
Which words correctly complete these statements?
N. 07 (23)
IGCSE
44.
Grade (10)
N. 07 (24)
The equation shows the reaction between a halogen and the aqueous ions of another
halogen.
X2
+ 2Y→
2X- + Y2
What could X2 and the colour of Y– be?
45. Element X exists as diatomic molecules.
In which group of the Periodic Table is X placed?
A.
B.
C.
D.
Group 0
Group I
Group II
Group VII
46. Which statement describes a test for carbon dioxide gas?
A.
B.
C.
D.
N. 07 (26)
J. 08 (21)
It bleaches damp litmus paper.
It relights a glowing splint.
It turns cobalt(II) chloride paper pink.
It turns limewater cloudy.
47. What is the colour of gaseous chlorine and of solid sodium chloride?
J. 08 (24)
IGCSE
Grade (10)
48. The Group I elements lithium and potassium are tested.
J. 08 (25)
Which element has the higher melting point and which element reacts more vigorously
with water?
49. The table gives information about four elements.
N. 08 (27)
Which element is a transition metal?
50. Which of the following compounds exist?
N. 08 (7)
IGCSE
51.
N. 08 (24)
Which properties of the element titanium, Ti, can be predicted from its position in the
Periodic Table?
52. The table gives information about four elements.
Which element could be in Group I of the Periodic Table?
53. What is the formula of a strontium ion?
A. Sr2+
B. Sr+
C. SrD. Sr2–
54.
Grade (10)
N. 08 (25)
N. 08 (26)
N. 08 (29)
A new isotope of a divalent metal is discovered. Some students are asked to predict its
properties.
Which student’s predictions are correct?
IGCSE
55.
Grade (10)
J. 09 (4)
An element S has the proton number 18. The next element in the Periodic Table is an
element T.
Which statement is correct?
A.
B.
C.
D.
Element T has one more electron in its outer shell than element S.
Element T has one more electron shell than element S.
Element T is in the same group of the Periodic Table as element S.
Element T is in the same period of the Periodic Table as element S.
56. The reactions shown may occur in the air during a thunder storm.
J. 09 (18)
N2
+ O2 →
2NO
2NO + O
→
2NO2
NO + O3 →
NO2 + O2
Which line shows what happens to the reactant molecules in each of these reactions?
57.
J. 09
Which statement describes the trends going down group VII of the Periodic Table?
A.
B.
C.
D.
(24)
The boiling point and melting point both decrease.
The boiling point and melting point both increase.
The boiling point decreases but the melting point increases.
The boiling point increases but the melting point decrease
58. The sulfate of element F is green.
Which other properties is element F likely to have?
J.09
(9)
IGCSE
Grade (10)
Paper 4
1.
J. 02 (4. a, b)
Bromine is one of the halogens in Group VII.
(a) (i) Predict which halogen has the lightest colour.
……………...............................................................................................................................[1]
(ii) Predict which halogens are solids at room temperature.
……………...............................................................................................................................[1]
(b) Bromine is obtained from the bromide ions in sea water. Sea water is concentrated by
evaporation. Chlorine gas is bubbled through the solution. Chlorine oxidises the
bromide ion to bromine.
(i) Complete the following equation.
Cl2
+
......Br–
...................
+ ..................
[2]
(ii) Explain using the idea of electron transfer why the bromide ion is oxidised by
chlorine.
The bromide ion is oxidised because ...................................................................................
…………...............................................................................................................................
Chlorine is the oxidising agent because ...............................................................................
……………........................................................................................................................... [2]
(ii) Name a reagent that can be oxidised by bromine molecules.
……………................................................................................................................................[1]
2.
N. 02 (2. a)
Manganese is a transition element. It has more than one valency and the metal and its
compounds are catalysts.
(a) (i) Predict three other properties of manganese that are typical of transition elements.
………....................................................................................................................................
…….....................................................................................................................................[3]
IGCSE
Grade (10)
(iii) Complete the electron distribution of manganese by inserting one number.
2 + 8 + .......... + 2
3.
[1]
N. 02 (3)
The elements in Period 3 and some of their common oxidation states are shown below.
Element
Oxidation State
Na
+1
Mg
+2
Al
+3
Si
+4
P
–3
S
–2
Cl
–1
Ar
0
(a) (i) Why do the oxidation states increase from sodium to silicon?
.............................................................................................................................................[ 1]
(ii) After Group(IV) the oxidation states are negative and decrease across the period.
Explain why.
………...................................................................................................................................
...........................................................................................................................................[2]
(b) The following compounds contain two elements. Predict their formulae.
aluminium sulfide ………………………………………………............................................
silicon phosphide ............................................................................................................. [2]
(c) Choose a different element from Period 3 that matches each description.
(i) It has a similar structure to diamond.
.............................................................................................................................................[1]
(ii)
It reacts violently with cold water to form a solution pH = 14.
.............................................................................................................................................[1]
(iii)
It has a gaseous oxide of the type XO2, which is acidic.
..............................................................................................................................................[1]
IGCSE
Grade (10)
(d) The only oxidation state of argon is zero. Why it is used to fill light bulbs?
……...........................................................................................................................................
……….....................................................................................................................................[1]
4.
J. 03 (2. a)
Calcium and other minerals are essential for healthy teeth and bones. Tablets can be taken
to provide these minerals.
(a) Boron is a non-metal with a macromolecular structure.
(i) What is the valency of boron?
……………………………………………………...........................................................................
(ii) Predict two physical properties of boron.
…………...................................................................................................................................
………...................................................................................................................................[3]
IGCSE
5.
Grade (10)
J. 03 (5. c)
The first three elements in Period 6 of the Periodic Table of the Elements are caesium,
barium and lanthanum.
(b) All three metals react with cold water. Complete the word equation for these reactions.
Metal
6.
+
water
................................. + .............................
[2]
N. 03 (3. c)
(c) A solution of an impure zinc ore contained zinc, lead and silver(I) ions. The addition of
zinc dust will displace both lead and silver.
(i) The ionic equation for the displacement of lead is as follows.
Which change is reduction? Explain your answer.
………...................................................................................................................................
...........................................................................................................................................[ 2]
(iii) Write an ionic equation for the reaction between zinc atoms and silver(I) ions.
………................................................................................................................................[2]
7.
J. 04 (1. c)
(c) Silicon is made by the carbon reduction of the macromolecular compound, silicon(IV)
oxide.
(i) Balance the equation for the reduction of silicon(IV) oxide.
SiO2
(ii)
+ …….
C
→
Si
+ …….. CO
[1]
Explain why the silicon(IV) oxide is said to be reduced.
……………………………………………………………………………………………………..[1]
IGCSE
(iii)
Grade (10)
Describe the structure of silicon(IV) oxide. You may use a diagram.
…..…………………………………………………………………………………………………[2]
8.
N. 04 (5. a)
Strontium and sulfur chlorides both have a formula of the type XCl 2 but they have
different properties.
(a) The formulae of the chlorides are similar because both elements have a valency of 2.
Explain why Group II and Group VI elements both have a valency of 2.
9.
J. 05 (1. a)
Three of the halogens in Group VII are:
chlorine
bromine
iodine
(a) (i) How does their colour change down the Group?
……………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(ii) How does their physical state (solid, liquid or gas) change down the Group?
……………………………………………………………………………………………………..[1]
(iv) Predict the colour and physical state of fluorine.
Colour…………………………………………………………………………………………….
physical state…………………………………………………………………………………. [2]
10.
J. 06 (1. a, b)
Iron is a transition element
.
(a) Which of the following statements about transition elements are correct?
Tick three boxes.
The metals are highly coloured e.g. yellow, green, blue.
The metals have low melting points.
Their compounds are highly coloured.
Their compounds are colourless.
The elements and their compounds are often used as catalysts.
They have more than one oxidation state.
. [3]
(b) (i) In which Period in the Periodic Table is iron to be found?
………………………………………………………………………………………………………[1]
(ii) Use the Periodic Table to work out the number of protons and the number of
neutrons in one atom of iron
number of protons = …………………………………………………………………………..
number of neutrons =…………………………………………..…………………………….. [1]
IGCSE
Grade (10)
11.
Use your copy of the periodic table to help you answer these questions.
(a) Predict the formula of each of the following compounds.
J. 07 (4. a, b, d, e)
(i) barium oxide ………………………………………………………………………………… [1]
(ii) boron oxide …………………………………………………………………………………. [1]
(b) Give the formula of the following ions.
(i) sulfide ……………………………………………………………………………….………….[1]
(ii) gallium ………………………………………………………………………. ……….………..[1]
(c) Potassium and vanadium are elements in Period IV.
(i) State two differences in their physical properties.
…………………………………………………………………………………………………………..
………………………………………………………………………………………………….…….[2]
(ii) Give two differences in their chemical properties.
…………………………………………………………………………………………………………..
………………………………………………………………..……………………………………….[2]
12.
For each of the following select an element from Period 4, potassium to krypton,
that matches the description
(a) It is a brown liquid at room temperature.
(d)
J.08 (1)
………………………….
It forms a compound with hydrogen having the formula XH4 .………………………….
(c) A metal that reacts violently with cold water.
.. …………………………
(d) It has a complete outer energy level.
…………………………
(e) It has oxidation states of 2 and 3 only.
…………………………
(f) It can form an ion of the type X-
.…………………………
(g) One of its oxides is the catalyst in the Contact Process
……………………… [Total: 7]
IGCSE
Grade (10)
Topic 6
Electricity and chemistry
• Electrolysis
• Applications of electrolysis
IGCSE
Grade (10)
Paper 2
1The diagram shows an electric heater.
J. 02
(12)
Which method would be used to plate the chromium on to the steel?
A. alloying
B. electrolysis
C. galvanising
D. Oxidation
2. The table shows some properties of four materials.
J. 02
(13)
Which of these materials are most suitable to make the pins and the case of an electric plug?
A.
B.
C.
D.
Pins
W
X
Y
Z
case
X
Z
W
Y
IGCSE
Grade (10)
3. The diagram represents the electrolysis of brine (aqueous sodium chloride).
N 02 (12)
What are products X and Y?
IGCSE
Grade (10)
4. The diagram shows how aluminium is manufactured by electrolysis.
J. 03
(12)
What are the anode and cathode made of?
5. A student sets up the apparatus shown. The bulb does not light.
After the student adds substance X to the water, the bulb lights.
What is X?
A. calcium carbonate
B. carbon
C. copper(II) sulfate
D. ethanol
J. 03
(13)
IGCSE
Grade (10)
6. The following electrolysis circuit is set up, using inert electrodes.
N. 03 (12)
At which electrode is a metal deposited?
7. The diagram shows a method used to electroplate a key with copper.
Which aqueous solution is most suitable for the electrolyte?
A.
B.
C.
D.
copper(II) sulfate
ethanol
sodium hydroxide
sulfuric acid
N. 03
(13)
IGCSE
Grade (10)
8. In the circuit shown the bulb does not light.
J. 04 (12)
Which change would cause the bulb to light?
A. add more solid copper(II) sulfate to the beaker
B. add water to dissolve the copper(II) sulfate
C. replace the carbon electrodes with copper electrodes
D. reverse the connections to the electrodes
9. The following electrolysis circuit is set up, using inert electrodes P, Q, R and S. J. 04 (3)
At which of the electrodes is a Group VII element produced?
A. P only
B. P and R
C. Q only
D. Q and S
10. Aluminium is extracted from its oxide by electrolysis.
N. 04 (12)
Which words correctly complete the spaces?
The oxide is dissolved in ……1…… cryolite and aluminium is deposited at the ……2……
IGCSE
11.
Grade (10)
N. 05 (13)
The diagram shows an electrolysis experiment using metals X and Y as electrodes.
One of the metals becomes coated with copper.
Which metal becomes coated and which aqueous solution is used?
12. Metallic and non-metallic elements can both be extracted by electrolysis.
Which element is produced at the negative electrode (cathode)?
J.05 (12)
A. bromine
B. chlorine
C. hydrogen
D. oxygen
13. Which product is manufactured by electrolysis?
A.
B.
C.
D.
aluminium
copper(II) sulfate
sodium chloride
Steel
J.05 (13)
IGCSE
14. The diagram shows the electrolysis of molten lead(II) bromide.
Grade (10)
N. 05
(10)
What is seen at each electrode?
15. The diagram shown is not complete.
N.05 (11)
What should be shown at X when the solution has been electrolysed for some time?
IGCSE
16.
Grade (10)
J. 06(11)
The diagram shows an electrolysis experiment to electroplate nickel with a different metal.
Which nickel electrodes are plated with a metal?
A. 1 only
B. 1 and 3 only
C. 2 only
D. 2 and 4 only
17.
18.
N. 06 (11)
The electrolysis of concentrated aqueous sodium chloride makes three products
Which products are shown at the correct electrodes?
N. 06 (12)
Aluminium is extracted from its oxide by electrolysis. To do so, the oxide is dissolved
Which substance is used to dissolve aluminium oxide and where is aluminium deposited
during the electrolysis?
IGCSE
19.
Grade (10)
J. 07 (12)
A molten compound is electrolysed. Two atoms of X are deposited at the negative
electrode at the same time as three atoms of Y are deposited at the positive electrode.
These results show that:
X is a …1…;
Y is a …2…;
the formula of the compound is …3… .
How are gaps 1, 2 and 3 correctly completed?
20.
J. 07 (13)
In which electrolysis are chlorine, hydrogen and sodium hydroxide all produced?
IGCSE
Grade (10)
21. A student sets up the apparatus shown. The bulb does not light.
N. 07 (9)
After the student adds substance X to the water, the bulb lights.
What could X be?
A. barium sulfate
B. carbon (or diamond)
C. copper (or graphite)
D. potassium sulfate
22.
N. 07 (12)
What is the charge on an anode and the type of element formed at such an electrode?
23. In which set of apparatus is the metal key electroplated with copper?
N. 07 (14)
IGCSE
24.
Grade (10)
J. 08 (13)
Two elements X and Y form ionic compounds, XBr2 and Y2O3. The compounds are
separately melted and electricity is passed through the liquids.
What are the products at the cathodes?
A. bromine and oxygen
B. bromine and Y
C. oxygen and X
D. X and Y
25. Which change can take place during electrolysis?
N. 08 (14)
A. lead(IV) oxide → lead(II) oxide + oxygen
B. concentrated hydrochloric acid → hydrogen + chlorine
C. sodium hydroxide + nitric acid →
sodium nitrate + water
D. lead(II) nitrate + sulfuric acid →
lead(II) sulfate + nitric acid
26. N. Which diagram shows an experiment in which the bulb lights?
N.08 (12)
IGCSE
Grade (10)
27.
N.08 (13)
Metal X is low in the reactivity series and it is liberated by electrolysis of its bromide. Metal X
is ……1…… and the bromide is ……2…… .
Which words correctly complete gaps 1 and 2?
28. Copper and hydrogen can each be formed by electrolysis.
J. 09
(14)
At which electrodes are these elements formed?
29. Aluminium is extracted from its oxide by electrolysis.
J. 09 (12)
The oxide is dissolved in ……1…… cryolite and aluminium is deposited at the ……2……
Which words correctly complete gaps 1 and 2?
IGCSE
Grade (10)
30. Molten lead(II) bromide is electrolysed as shown. .
J. 09 (14)
Which ions are discharged at each electrode?
31.
J. 09 (15)
Which of these elements could be formed at the anode when a molten salt is electrolysed?
A.
B.
C.
D.
copper
iodine
lithium
strontium
IGCSE
Grade (10)
Paper 4
1.
J. 02 (1. b)
(b) Aluminium is produced by the electrolysis of an electrolyte that contains aluminium
oxide.
(i) Write an ionic equation for the reduction of the aluminium ion at the cathode.
……...................................................................................................................................[2]
(ii) Name the main ore of aluminium.
……...................................................................................................................................[1]
(ii) Complete the following description of the electrolyte by filling the spaces.
The electrolyte is a ................................................ mixture of aluminium oxide
and .................................................. which is maintained at 900 °C.
[2]
(iv) Explain why the gas given off at the anode is a mixture of oxygen and carbon
dioxide.
…....................................................................................................................................
……................................................................................................................................[2]
2.
N. 02 (4. b, c)
(b) Copper is refined by the electrolysis of aqueous copper(II) sulfate using copper
electrodes. Describe the change that occurs at the electrodes.
(i) cathode (pure copper) ...............................................................................................
…................................................................................................................................[1]
(ii)
anode (impure copper) ..............................................................................................
…..................................................................................................................................[1]
(iii)
Write an ionic equation for the reaction at the cathode.
….................................................................................................................................[1]
IGCSE
Grade (10)
(iv) If carbon electrodes are used, a colourless gas is given off at the anode and the
electrolyte changes from a blue to a colourless solution.
The colourless gas is ................................................. .
The solution changes into .......................................... .
[2]
(c) Electrolysis and cells both involve chemical reactions and electricity.
What is the essential difference between them?
............................................................................................................................................
...........................................................................................................................................[2]
3.
J. 03 (1. e)
(e) One of the methods used to prevent iron or steel from rusting is to electroplate it with
another metal, such as tin. Complete the following.
The anode is made of ............................................... .
The cathode is made of ............................................. .
The electrolyte is a solution of ................................... .
[3]
4.
J. 03 (5. b)
(b) All three metals can be obtained by the electrolysis of a molten halide. The electrolysis
of the aqueous halides does not produce the metal.
(i) Complete the equation for the reduction of lanthanum ions at the negative
electrode (cathode).
La3+
(iii)
+
................
................
Name the three products formed by the electrolysis of aqueous caesium bromide.
.......................................................................................................................................
...................................................................................................................................[4]
IGCSE
5.
Grade (10)
J. 04 (5. b, c)
(b) Aqueous copper(II) sulfate solution can be electrolysed using carbon electrodes.
The ions present in the solution are as follows
Cu2+(aq) , SO42– (aq), H+(aq),
(i)
OH– (aq)
Write an ionic equation for the reaction at the negative electrode (cathode).
……………………………………………………………………………………………………[1]
(ii) A colourless gas was given off at the positive electrode (anode) and the solution
changes from blue to colourless.
Explain these observations.
…………………………………………………………………………………………………[2]
(c) Aqueous copper(II) sulfate can be electrolysed using copper electrodes. The
reaction at the negative electrode is the same but the positive electrode becomes
smaller and the solution remains blue.
(i) Write a word equation for the reaction at the positive electrode.
…………………………………………………………………………………………………….[1]
(ii)
Explain why the colour of the solution does not change.
……………………………………………………………………………………………………..[2]
(iii)
What is the large scale use of this electrolysis?
……………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
6.
J. 05 (6. a)
The position of aluminium in the reactivity series of metals is shown below.
magnesium
aluminium
zinc
copper
(a) Aluminium is extracted by the electrolysis of its molten oxide.
(i) Name the main ore of aluminium.
……………………………………………………………………………………………………….[1]
(ii) Why does the molten electrolyte contain cryolite?
……………………………………………………………………………………………………….[1]
(iii) Oxygen is produced at the positive electrode (anode). Name another gas which is
given off at this electrode.
…………………………………………………………………………………………………….[1]
7.
N. 05 (5. c)
(c) The major ore of strontium is its carbonate, SrCO3. Strontium is extracted by the
electrolysis of its molten chloride.
(i) Name the reagent that will react with the carbonate to form the chloride.
………………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(ii) The electrolysis of molten strontium chloride produces strontium metal and
chlorine. Write ionic equations for the reactions at the electrodes.
negative electrode (cathode)………………………………………………………………….
positive electrode (anode)…………………………………………………………………… [2]
(iii) One of the products of the electrolysis of concentrated aqueous strontium chloride
is chlorine. Name the other two.
………………………………………………………………………….…………………………
……………………………………………………………………………………………………[2]
8.
N.06 (6. b)
(b) Impure copper is extracted from the ore. This copper is refined by
electrolysis.
(i) Name :
the material used for the positive electrode (anode),…………………………………………….
the material used for the negative electrode (cathode),……………………………………..….
a suitable electrolyte……………………………………………………………………..………[3]
(ii)
Write an ionic equation for the reaction at the negative electrode.
……………………………………………………………………….…………………………….[1]
(iv) One use of this pure copper is electrical conductors, another is to make alloys.
Name the metal that is alloyed with copper to make brass.
……………………………………………………………………………………………..…….[1]
IGCSE
Grade (10)
9.
J. 07 (6. b, c)
(b) Complete the labelling of the diagram.
(c) The ions that are involved in the electrolysis are Al3+ and O2-.
(i) Write an equation for the reaction at the cathode.
……………………………………………………………………………………………………….[2]
(ii) Explain how carbon dioxide is formed at the anode.
…………………………………………………………………………………….………………….[2]
10.
N. 07 (4. c)
(d) The remaining zinc oxide reacts with sulfuric acid to give aqueous zinc
sulfate.
This is electrolysed with inert electrodes (the electrolysis is the same as that of is
electrolysed with inert electrodes (the electrolysis is the same as that of copper(II)
sulfate with inert electrodes) ions present:
Zn2+(aq)
SO42-(aq)
H+(aq)
OH-(aq)
(i) Zinc forms at the negative electrode (cathode). Write the equation for this
reaction.
…………………………………………………………………………………….……………...[1]
IGCSE
Grade (10)
(ii) Write the equation for the reaction at the positive electrode (anode).
…………………………………………………………………………..……………….…………
…………………………………………………………………………………………………… [2]
(iii) The electrolyte changes from aqueous zinc sulfate to
………………………………………………………………………………..…………………..[1]
(e) Give two uses of zinc.
1………………………………………………………..……………………………………………
2……………………………………………………………….………………………………….. [2]
11.
J. 08 ( 3. a)
Copper is purified by electrolysis.
(a) Complete the following.
The positive electrode (anode) is made from………………………………… ……………….
The negative electrode (cathode) is made from……………………………………..………...
The electrolyte is aqueous……………………………………………………………………… [3]
(b) Write an ionic equation for the reaction at the positive electrode (anode).
………………………………………………………………………………………..………………..
………………………………………………………………………………………………………..[2]
12.
N. 08 (5. a)
The electrolysis of concentrated aqueous sodium chloride produces three commercially
important chemicals; hydrogen, chlorine and sodium hydroxide.
(a) The ions present are
Na+(aq),
H+(aq)
Cl–(aq)
and
OH–(aq).
(i) Complete the ionic equation for the reaction at the negative electrode (cathode).
…………………..
+ ………………….
H2
[1]
IGCSE
Grade (10)
(ii) Complete the ionic equation for the reaction at the positive electrode (anode).
2Cl –
(iii)
−
…………….
………………..
[1]
Explain why the solution changes from sodium chloride to sodium hydroxide.
………………………………………………………………………………………………….[1]
13.
J. 09 (2)
The results of experiments on electrolysis using inert electrodes are given in the table.
Complete the table; the first line has been completed as an example.
IGCSE
Grade (10)
Paper 6
1.
N. 01 (2)
A metal cup can be coated in silver by electrolysis. The cup must be very clean and also
rotated during the process, which is known as electroplating.
(a) Should the metal cup be the anode or the cathode?
..............................................................................................................................................[1]
(b) Identify the metal from which the electrode is made.
..............................................................................................................................................[1]
(c) Suggest a suitable electrolyte that could be used to electroplate this cup.
..............................................................................................................................................[2]
(d) Suggest why the cup must be
(i) very clean, ................................................................................................................
......................................................................................................................................... .[1]
IGCSE
Grade (10)
(ii) rotated during the electrolysis. ..................................................................................
............................................................................................................................................[1]
2.
J. 05 (2)
The diagram shows the apparatus used to find out the effect of an electric current on a
concentrated aqueous solution of sodium chloride.
(a) On the diagram label the electrodes
[1]
(c) Give three observations when the circuit is switched on.
1……………………………………………………………………………………………………….
2……………………………………………………………………………………………………….
3……………………………………………………………………………………………………… [3]
(d) (i) Name the product at the positive electrode (anode).
………………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
3.
N. 05 (2. a, b)
The diagram shows the apparatus used to pass an electric current through concentrated
hydrochloric acid.
(a) Label the electrodes.
[1]
(b) Give two observations when the current is switched on.
1…………………………………………………………………………………………………………
2……………………………………………………………………………………………………….. [2]
IGCSE
Grade (10)
4.
J. 08 (2)
The diagram shows an experiment to pass electricity through lead bromide.
Electricity has no effect on solid lead bromide.
(a) (i) Clearly label the electrodes on the diagram.
[1]
(iii) Suggest a suitable material to make the electrodes.
…………………………………………………………………………………………………. [1]
(b) Give two observations expected when the lead bromide is heated to melting point.
1………………………………………………………………………………………………………
2…………………………………………………………………………………………………….. [2]
(c) State two different safety precautions when carrying out this experiment.
1……………………………………………………………………………………………………….
2…………………………………………………………………………………………………….. [2]
IGCSE
Grade (10)
Topic 7
Acids, bases and salts
• Acids
• Bases
• The pH Scale
• Making salts
• Types of oxide
• Identification of ions
IGCSE
Grade (10)
Paper 2
1. . Hydrochloric acid is used to clean metals.
J. 02 (19)
The acid reacts with the oxide layer on the surface of the metal, forming a salt and water.
Which word describes the metal oxide?
A. alloy
B. base
C. element
D . indicator
2. Which substance reacts with calcium to form a salt?
A. hydrochloric acid
B. oxygen
C. sodium hydroxide
D . water
J. 02
(20)
3. The incomplete equation shows a reaction.
CuCO3
+
H2SO4
products
What are the products of this reaction?
A copper(II) oxide, sulfur dioxide, hydrogen
B copper(II) oxide, sulfur dioxide, water
C copper(II) sulfate, carbon dioxide, hydrogen
D copper(II) sulfate, carbon dioxide, water
J. 02
(21)
4.
N. 02
One method of producing carbon dioxide is to react calcium carbonate with dilute
hydrochloric acid.
What is the balanced chemical equation for the reaction?
A. CaCO3 + HCl
CaO + CO2 + HCl
B. CaCO3 + 2HCl
CaCl2 + CO2 + H2O
C. CaCO3 + 4HCl
CaCl4 + CO2 + H2 + H2O
D. Ca(HCO3)2 + HCl
CaCl + 2CO2 + H2O
(9)
5.
N. 02 (19) / J.07 (22)
Aqueous lead(II) nitrate is added to a solution containing iodide ions. Lead(II) iodide is
formed.
Which type of reaction takes place?
A. neutralisation
B. oxidation
C. precipitation
D. reduction
IGCSE
Grade (10)
6. For which pH change is there the largest increase in acidity?
N. 02 (21)
7. Water is added to a test-tube containing dilute sulfuric acid of pH 4.
What could be the pH of the resulting solution?
A. 8
B. 6
C. 4
J. 03
(21)
D. 2
8.
N. 03 (17)
The equation shows what happens when hydrated copper(II) sulfate is heated.
CuSO4.5H2O(s)
CuSO4(s) +
5H2O(g)
What can be deduced from the equation?
A. The hydrated copper(II) sulfate is oxidised.
B. The hydrated copper(II) sulfate is reduced.
C. The reaction is reversible.
D. There is no colour change.
9.
N. 03 (19)
Which two processes are involved in the preparation of magnesium sulfate crystals from
dilute sulfuric acid and an excess of magnesium oxide?
A. decomposition and filtration
B. decomposition and oxidation
C. neutralisation and filtration
D. neutralisation and oxidation
IGCSE
10. The diagram shows the result of testing an aqueous solution Z.
Grade (10)
N. 03 (20)
Which ion is present in solution Z?
A. carbonate
B. chloride
C. nitrate
D. sulfate
11. The pH values of four solutions are shown.
N. 03
Mixing combinations of these solutions can give a solution of pH 6.
Which combination of solutions could not do this?
A. P and R
B. P and S
C. Q and R
D. R and S
12. Measurements are made on some pure water.
its boiling point, b.p.
its freezing point, f.p.
its pH
Sodium chloride is now dissolved in the water and the measurements repeated.
Which measured values change?
(21)
IGCSE
Grade (10)
13. An aqueous solution contains either aluminium sulfate or zinc sulfate. J. 04 (19)
Which aqueous reagent can be used to confirm which salt is present?
A. ammonia
B. barium chloride
C. sodium hydroxide
D. sulfuric acid
14.
J. 04 (20)
Aqueous sodium hydroxide is added to two different solutions with the results shown.
Which cation is present in X and in Y?
15.
J. 04 (30)
The pH of some aqueous sodium hydroxide is measured. The solution is then distilled as
shown.
How do the pH values of the distillate and of the solution left in the flask compare with the
original?
IGCSE
Grade (10)
16. Which property does hydrochloric acid have?
J. 05
(19)
A. It gives a pale blue precipitate with aqueous copper(II) sulfate.
B. It gives a white precipitate with aqueous barium nitrate.
C. It releases ammonia from aqueous ammonium sulfate.
D. It releases hydrogen with zinc powder.
17.
J. 05
(20)
Hydrochloric acid is used to clean a metal surface by removing the oxide layer on the metal.
This is because hydrochloric acid has a …..X….. pH and the metal oxide is …..Y…..
What are X and Y?
18. The apparatus shown can be used to prepare aqueous copper(II) sulfate
What are substances X and Y?
J. 05 (21)
IGCSE
19.
Grade (10)
J. 05 (22)
In the experiment shown, the dilute sulfuric acid is run into the flask of aqueous barium
hydroxide until the reaction is complete.
Which processes occur in this reaction?
20.
J. 05 (34)
The presence of nitrates in soil can be shown by warming the soil with aqueous sodium
hydroxide and aluminium foil.
Which gas is given off?
A. ammonia
B. carbon dioxide
C. nitrogen
D. nitrogen dioxide
IGCSE
Grade (10)
21. Bottles of sodium hydroxide, sodium chloride and sugar have lost their labels.
Students test a sample from each bottle. Their results are shown in the table.
N. 05 (7)
What are the correct labels for each bottle?
22.
N. 05
(16)
An excess of acid in the stomach causes indigestion that can be cured by an
anti- indigestion tablet.
What should the tablet contain to decrease the acidity?
A. an acidic substance
B. an alkaline substance
C. a neutral substance
D. Universal Indicator
23. A solution is made by adding sodium oxide to water.
Which pH change can occur?
N. 05 (16)
IGCSE
Grade (10)
24. Which element has an oxide that forms a salt with an alkali?
A. N
25.
B. Na
C. Ne
N. 05
(18)
D. Ni
N. 05 (19)
Pure zinc sulfate can be prepared by adding an excess of either zinc carbonate or an
excess of zinc hydroxide to dilute sulfuric acid
In which form are these zinc compounds used?
26.
N. 05 (20)
Which aqueous ion causes a yellow precipitate to form when acidified aqueous lead(II)
nitrate is added to it?
A. chloride
B. iodide
C. nitrate
D. sulfate
IGCSE
Grade (10)
27. The diagrams show three experiments.
In which experiments is ammonia formed?
A. 1 only
B. 2 only
N. 05 (31)
C. 3 only
D. 1, 2 and 3
28. Acids react with bases, carbonates and metals.
Which of these reactions produce a gas?
N. 06 (17)
29. Which properties does an acid have?
1 reacts with ammonium sulfate to form ammonia
2 turns red litmus blue
N. 06 (20)
IGCSE
Grade (10)
30.
N. 06 (21)
The diagrams show two experiments, one to make barium chloride and the other to make
barium sulfate.
In each experiment, the acid is run into the conical flask until the resulting liquid has pH7.
What are the next steps to obtain samples of the solid salts?
31. The statements are about metals and their oxides.
Metals …X… electrons to form ions. The oxides of metals are …Y….
Which words correctly complete the statements?
N. 06
(21)
IGCSE
32. Gas X is passed into water as shown.
Grade (10)
N. 07 (19)
The pH of the water changes from 7 to 10.
What is gas X?
A. ammonia
B. carbon dioxide
C. nitrogen
D. sulfur dioxide
33.
N. 07 (21)
Two tests are carried out on a solution containing both copper(II) sulfate and sodium chloride.
A student records results as shown.
Which results are correctly recorded?
34.
N. 07 (21)
Aqueous solution S is added to aqueous ammonium chloride. The mixture is heated.
Ammonia gas is given off.
What could solution S contain?
A. aluminium
B. ammonium sulfate
C. sodium chloride
D. sodium hydroxide
IGCSE
Grade (10)
35.
J. 08 (19)
The equation explains the colour change that occurs when aqueous potassium hydroxide is
added to aqueous potassium dichromate(VI).
K2Cr2O7
+
Potassium
dichromate(VI)
orange
2KOH
→
2K2CrO4 + H2O
potassium
chromate(VI)
yellow
As a result of adding an excess of aqueous potassium hydroxide to aqueous potassium
dichromate(VI), what happens to the oxidation state of the chromium and the pH of the
reaction mixture?
IGCSE
Grade (10)
Paper 4
1.
J. 02 (2. a)
(a) Vines are attacked by a fungus that ruins the grapes. In 1882 it was discovered that
spraying the vines with Bordeaux mixture killed the fungus.
The fungicide, Bordeaux mixture, contains water, calcium hydroxide and copper(II)
sulfate.
(ii) The mixture contains four ions. Complete the list of ions.
Cu2+,
OH–,
......................... and .............................
[2]
(iii) A different fungicide can be made by the reaction between an excess of aqueous
ammonia and a copper(II) salt. Describe the observations for this reaction.
addition of aqueous ammonia .........................................................................................
........................................................................................................................................
then excess aqueous ammonia .....................................................................................
…...............................................................................................................................[3]
2.
(d) Phosphorus tribromide reacts with water to form two acids.
(i) Balance the equation for this reaction.
PBr3 + ......H2O
..... HBr
+
J. 02
(4. d, e)
H3PO3
[1]
(ii) Describe by giving essential details how you could show that
phosphorous acid, H3PO3, is a weaker acid than hydrogen bromide.
………....................................................................................................................................
………....................................................................................................................................
……....................................................................................................................................[2]
(e) Hydrogen bromide is an acid. When it is dissolved in water the following
reaction occurs.
HBr + H2O
H3O+ +
Br–
(i) Name the particle lost by the hydrogen bromide molecule.
…..................................................................................................................................[1]
IGCSE
Grade (10)
(ii) What type of reagent is the water molecule in this reaction?
…… ...............................................................................................................................[1]
3.
There are three ways of making salts from sulfuric acid.
N. 02 (1. b)
titration using a burette and indicator
precipitation by mixing the solutions and filtering
neutralisation of sulfuric acid using an excess of an insoluble base
Complete the following table of salt preparations.
4.
N. 02 (2. b)
Manganese is a transition element. It has more than one valency and the metal and its
compounds are catalysts.
(b) It has several oxides, three of which are shown below.
Manganese(II) oxide, which is basic.
Manganese(III) oxide, which is amphoteric.
Manganese(IV) oxide, which is acidic.
(i) Complete the word equation.
manganese(II) + hydrochloric
oxide
acid
........................... + ..........................
[2]
(ii) Which, if any, of these oxides will react with sodium hydroxide?
……................................................................................................................................[1]
IGCSE
5.
Grade (10)
J. 03 (2. b)
(b) Describe the reactions, if any, of zinc and copper(II) ions with an excess of aqueous
sodium hydroxide.
(i) zinc ions
addition of aqueous sodium hydroxide ...........................................................................
excess sodium hydroxide ...............................................................................................
(ii) copper(II) ions
addition of aqueous sodium hydroxide ...............................................................................
excess sodium hydroxide …………................................................................................[4]
6.
J. 03 (4, d)
(d) Nitrogen dioxide, oxygen and water react to form dilute nitric acid.
Describe how lead(II) nitrate crystals could be prepared from dilute nitric acid and
lead(II) oxide.
...........................................................................................................................................
...........................................................................................................................................
........................................................................................................................................[3]
7.
J. 04 (2. b)
(iv) The ionic equation for the reaction between the phosphate ion and sulfuric acid
is shown below.
PO43–
+
2H2SO4
→
H2PO4–
+
2HSO4–
Explain why the phosphate ion is described as acting as a base in this reaction.
………………………………………………………………………………………………..[2]
8.
J. 04 (4)
(a) Insoluble compounds are made by precipitation.
(i)
Complete the word equation for the preparation of zinc carbonate.
……………… +
………………
sodium
carbonate
→
……………………
…………………...
+
zinc
carbonate
[2]
IGCSE
Grade (10)
(ii) Complete the following symbol equation.
Pb(NO3)2 + …… NaCl
(ii)
→
………………..
+
………………………
[2]
Write an ionic equation for the precipitation of the insoluble salt, silver(I) chloride.
…………………………………………………………………………………………………… [2]
(b) 2.0 cm3 portions of aqueous sodium hydroxide were added to 4.0 cm3
of aqueous iron(III) chloride. Both solutions had a concentration of 1.0 mol/dm3
After each addition, the mixture was stirred, centrifuged and the height of the precipitate of
iron(III) hydroxide was measured. The results are shown on the following graph.
(i) Complete the ionic equation for the reaction.
Fe3+ + …..OH– → ……………….
(ii) On the same grid, sketch the graph that would have been obtained if iron(II) chloride
had been used instead of iron(III) chloride?
[1]
[2]
(iii) If aluminium chloride had been used instead of iron(III) chloride, the shape of the
graph would be different. How are the shapes of these two graphs different and why?
difference in shape………………………………………………………………………………….
……………………………………………………………………………………………………….
IGCSE
Grade (10)
reason for difference………………………………………………………………………………..
………………………………………………………………………………………………………[2]
9.
N. 04 (2)
The salt copper(II) sulfate can be prepared by reacting copper(II) oxide with sulfuric
acid.
Complete the list of instructions for making copper(II) sulfate using six of the words below.
Blue
Saturated
cool
sulfate
dilute
white
filter
oxide
Instructions
10.
J. 05 (2. b)
(b) Describe how you could show by adding aqueous sodium hydroxide and aqueous
ammonia that a solution contained zinc ions.
result with sodium hydroxide…………………………………………………………………….
excess sodium hydroxide………………………………………………………………………..
result with aqueous ammonia……………………………………………………………………
excess aqueous ammonia…………………………………………………………………… [3]
IGCSE
Grade (10)
11.
J. 05 (3. b, d)
A South Korean chemist has discovered a cure for smelly socks. Small particles of silver
are attached to a polymer, poly(propene), and this is woven into the socks
(b) To show that the polymer contains silver the following test was carried out.
The polymer fibers were chopped into small pieces and warmed with nitric acid. The
silver atoms were oxidised to silver(I) ions. The mixture was filtered. Aqueous sodium
chloride was added to the filtrate and a white precipitate formed.
(i) Why was the mixture filtered?
………………………………………………………………………………………………………[1]
(ii) Explain why the change of silver atoms to silver ions is oxidation.
……………………………………………………………………………………………………[1]
(iii) Give the name of the white precipitate.
…………………………………………………………………………………………………...[1]
(d) Propanoic acid is a weak acid.
(i) The following equation represents its reaction with ammonia.
CH3 CH2 COOH
+
NH3
CH3 CH2 COO–
+ NH4+
Explain why propanoic acid behaves as an acid and ammonia as a base.
………………………………………………………………………………………………………
……………………………………………………………………………………………………..[3]
(ii) Explain the expression weak acid.
……………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
12.
N. 05 (6. b)
(b) In the above method, a soluble salt was prepared by neutralising an acid with an
insoluble base. Other salts have to be made by different methods.
(i) Give a brief description of how the soluble salt, rubidium sulfate could be made
from the soluble base, rubidium hydroxide.
……………………………………………………………………………………………………
……………………………………………………………………………………………………..
…………………………………………………….……………………………………………..
…………………………………………………………………………………………………..[3]
(iii) Suggest a method of making the insoluble salt, calcium fluoride.
……………………………………………………………………………………………………
…………………..……………………………………………………………………………….
…………………………………………………………………………………………………..[3]
13.
J. 06 (3)
(a) Four bottles were known to contain aqueous ammonia, dilute hydrochloric acid, sodium
hydroxide solution and vinegar, which is dilute ethanoic acid. The bottles had lost their
labels. The pH values of the four solutions were 1, 4, 10 and 13.
Complete the table.
IGCSE
Grade (10)
(b) The following apparatus was set up to investigate the electrical conductivity of dilute
acids.
Dilute sulfuric acid is a strong acid. If it was replaced by a weak acid, what two
differences in the observations would you expect to make?
………………………………………………………………………………………………………...
………………………………………………………………………………………………………..[2]
(b) When nitric acid is added to water the following reaction occurs.
HNO3 +
NO3 -
H2O
+
H3O+
Give the name and the formula of the particle which is transferred from nitric acid to
water.
Name…………………………………………………………………………….……………………
Formula……………………………………………………………………………………………. [2]
(d) This question is concerned with the following oxides.
aluminium oxide
calcium oxide
carbon dioxide
carbon monoxide
magnesium oxide
sulfur dioxide
Al2O3
CaO
CO2
CO
MgO
SO2
(i) Which of the above oxides will react with hydrochloric acid but not with aqueous
sodium hydroxide?
………………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(ii) Which of the above oxides will react with aqueous sodium hydroxide but not with
hydrochloric acid?
………………………………………………………………………………………………………[1]
(iii) Which of the above oxides will react both with hydrochloric acid and with aqueous
sodium hydroxide?
……………………………………………………………………………………………………[1]
(iv) Which of the above oxides will react neither with hydrochloric acid nor with aqueous
sodium hydroxide?
……………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
Paper 6
1.
J. 02 (6)
Two solid compounds S and T were tested. The tests on S and T and some of the
observations are in the following table. S was copper(II) oxide. Complete the observations
in the table.
IGCSE
Grade (10)
(e) Name the gas given off in test (b)(ii).
................................................................................................................................................[1]
(f) Name the gas given off in test (c)(i).
.................................................................................................................................................[1]
(g) What conclusions can you draw about solid T?
..................................................................................................................................................
.................................................................................................................................................[2]
2.
J. 02 (7. a, c)
Describe a chemical test to distinguish between each of the following pairs of substances.
An example is given.
potassium chloride and potassium iodide
test:
add aqueous lead(II) nitrate
result:
potassium chloride gives a white precipitate, potassium iodide gives a yellow
precipitate
(a) hydrochloric acid and aqueous sodium chloride
test ......................................................................................................................................
result ...................................................................................................................................
............................................................................................................................................. [2]
IGCSE
3.
Grade (10)
03 (4)
A mixture of two solid compounds D and E was analysed. Solid D was a zinc salt which is
soluble in water. Solid E was an insoluble metal carbonate. The tests on the mixture and
some of the observations are in the following table.
Complete the observations in the table.
IGCSE
Grade (10)
(f) What conclusions can you draw about the identity of solid D?
...............................................................................................................................................
..............................................................................................................................................[2]
(g) What conclusions can you draw about the identity of the cation in solid E?
...............................................................................................................................................
..............................................................................................................................................[2]
IGCSE
4.
Grade (10)
J. 04 (5)
A mixture of two calcium compounds C and D was tested.
C is partially soluble in water and D is soluble in water.
Complete the observations in the table.
(b) Name the gas given off in (a)(iii).
……………………………………………………………………………………………………..[1]
(c) Suggest an explanation for the observation in (a)(v).
………………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
(d) What conclusions can you draw about the identity of the anions in solid C and D?
………………………………………………………………………………………………………..
………………………………………………………………………………..………………………[2]
5.
J. 04 (7. b, c)
Describe a chemical test to distinguish between each of the following pairs of substances.
An example is given.
potassium chloride and potassium iodide
test:
add aqueous lead(II) nitrate
result:
potassium chloride gives a white precipitate,
potassium iodide gives a yellow precipitate
(e) sulfuric acid and aqueous sodium sulfate
Test…………………………………………………………………………………………………..
result with sulfuric acid…………………………………………………………………………….
result with aqueous sodium sulfate……………………………………………………………. [2]
(c) hydrochloric acid and nitric acid
Test……………………………………………………………………………………………………
result with hydrochloric acid………………………………………………………………………
result with nitric acid…………………………………………………………………………… [2]
IGCSE
6.
Grade (10)
J. 05 (5)
A sample of a solution of acid A was analysed.
The tests on A, and some of the observations are in the following table.
1. Complete the observations in the table.
(a) What does test (a) tell you about the type of acid in solution A?
……………………………………………………………………………………………………..[1]
(b) (i) Name the gas given off in test (b)(i).
………………………………………………………………………………………………………..[1]
(i)
Name the gas given off in test (b)(ii).
………………………………………………………………………………………………………..[1]
(c) Explain the observations in test (b)(iii).
………………………………………………………………………………………………………..[2]
IGCSE
Grade (10)
7. A mixture of two compounds, B and C, was tested.
Compound B was a water-soluble zinc salt and compound C was insoluble.
The tests and some of the observations are in the following table.
Complete the observations in the table.
J. 06 (5)
IGCSE
Grade (10)
(d) What does test (a) indicate?
……………………………………………………………………………………………………….[1]
(e) What conclusions can you draw about compound B?
………………………………………………………………………………………………………..
………………………………………………………………………………………………………..[2]
(f) What does test (c) indicate?
……………………………………………………………………………………………………….
………………………………………………………………………………………………………...[2]
IGCSE
8.
Grade (10)
N. 08 (5)
Two salt solutions K and L were analysed. Each contained the same chloride anion but
different metal cations. K was a copper(II) salt.
The tests on the solutions and some of the observations are in the following table.
Complete the observations in the table
.
IGCSE
Grade (10)
(e) What does test (b) indicate?
……………………………………………………………………………………………………..[1]
(f) Identify the metal cation present in solution L.
………………………………………………………………………………………………………[2]
IGCSE
Grade (10)
Topic 8
Metals and reactivity series
• Alloys
• Reactivity series
• Extraction of iron
• Steel making
• Extraction of zinc
• Rusting
IGCSE
Grade (10)
Paper 2
1. The table shows the properties of four metals.
Which metal would be the best to make the body of an aircraft?
J. 02 (24)
2. Which oxide can be reduced by heating it with carbon?
J. 02 (25)
A. aluminium oxide
B. calcium oxide
C. copper(II) oxide
D. potassium oxide
3. A highly reactive metal is likely to
N. 02 (26)
A. form negative ions,
B. occur naturally as an element,
C. occur only as an oxide,
D. oxidise rapidly in air.
4. The diagram shows the manufacture of steel.
What could gas X be?
A. carbon dioxide
B. chlorine
C. hydrogen
D. oxygen
N. 02 (27)
IGCSE
Grade (10)
5. A student writes the following statements.
N. 02 (28)
1 Aluminium is used in the manufacture of aircraft bodies.
2 Aluminium is used to make stainless steel.
3 Mild steel is used in the manufacture of car bodies.
Which statements are correct?
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
6. Why does a bicycle chain that is coated with oil not rust?
N. 02 (32)
A. Oil dissolves any rust that forms.
B. Oil reacts with rust causing oxidation.
C. Oil reacts with oxygen so no rust forms.
D. Oil stops oxygen and water getting to the chain.
7.
J.03 (19)
Which substance does not form copper(II) sulfate with warm, dilute sulfuric acid?
A. copper
B. copper(II) carbonate
C. copper(II) hydroxide
D. copper(II) oxide
8. Which material is an alloy that contains a non-metallic element?
A. brass
B. haematite
C. manganese
D. steel
J.03 (25)
IGCSE
Grade (10)
9. The table gives information about the reactivity of three metals P, Q and R.
J.03 (26)
What is the order of reactivity of P, Q and R?
10. The bodies of aircraft are often made using aluminium.
J.03 (27)
Which two properties of aluminium make it suitable for this purpose?
11. Which raw materials are used in the manufacture of iron?
A. bauxite and lime
B. bauxite and limestone
C. haematite and lime
D. haematite and limestone
J.03 (28)
IGCSE
Grade (10)
12.
J.03 (32) / N. 07 (33)
Which methods can be used to prevent the rusting of an iron girder of a bridge?
13. Which property do all metals have?
J. 04 (23) / J.09 (30)
A. They are hard.
B. They conduct electricity.
C. They form acidic oxides.
D. They react with water.
14.
N. 03 (26) / J. 07 (29)
The diagram shows a method for changing a metal oxide into a metal. Which oxide can
be changed into a metal by using this method?
A. calcium oxide
B. copper(II) oxide
C. magnesium oxide
D. potassium oxide
15. The table shows properties of four elements. .
Which element is used to make aircraft bodies?
N. 03 (27)
IGCSE
16.
Grade (10)
N. 03 (28)
Three metals X, Y, and Z are correctly placed in the reactivity series as shown.
most reactive potassium
X
sodium
zinc
Y
iron
copper
least reactive Z
How are X, Y and Z obtained from their ores?
17. The apparatus shown is set up and left for a week.
Where would the water level be at the end of the week?
N. 03 (32)
IGCSE
Grade (10)
18. Three metals are extracted as shown in the table.
J. 04 (26)
What is the order of reactivity of the metals?
19. Haematite is reduced to iron in the blast furnace.
Haematite
+ carbon monoxide
→
iron
J. 04 (27)
+
X
What is X?
A. carbon
B. carbon dioxide
C. hydrogen
D. oxygen
20. Which object is least likely to contain aluminium?
A. a bicycle frame
B. a hammer
C. a saucepan
D. an aeroplane body
J. 04 (28)
IGCSE
21.
Grade (10)
J. 04 (32)
An old railway carriage is being restored. Metal strips are secured on to the outside of the
wooden carriage by means of screws. After a few weeks open to the wind and rain, the
screws are heavily corroded but the metal strips are not.
Aluminium is more reactive than both steel and copper.
Which two metals would give this result?
22. Which two elements form an alloy when they are heated together?
A. chlorine and hydrogen
B. chlorine and zinc
C. copper and hydrogen
D. copper and zinc
23. Mild steel is an alloy of iron and carbon.
How does the carbon affect the properties of mild steel?
J. 05 (9)
J. 05 (27) l N.08 (28)
A. The carbon makes the alloy a better conductor of electricity than iron.
B. The carbon makes the alloy harder than the iron.
C. The carbon makes the alloy softer than the iron.
D. The carbon stops the iron rusting.
24. Which metal reacts quickly with cold water only when it is finely powdered?
A. calcium
B. copper
C. sodium
D. magnesium
J. 05 (28)
IGCSE
Grade (10)
25.
J. 05 (29)
Which of the oxides CaO, CuO and Na2O can be reduced by heating with carbon?
A. CaO only
B. CuO only
C. Na2O only
D. CaO, CuO and Na2O
26. Three stages in making steel from iron ore are listed.
J. 05 (30)
X carbon dioxide reacts with carbon
Y basic oxides and oxygen are added
Z hematite is reduced
In which order do these stages occur?
A. X → Y → Z
B. X → Z → Y
C. Y → X → Z
D. Z → Y → X
27. Which methods prevent rusting of iron?
28. Two reactions involving water are shown.
X FeSO4 + water → hydrated iron(II) sulfate
Y Fe + O2 + water → rust
Which of these reactions are reversible by heating?
J. 05 (32) / N. 07 (33)
J. 06
(14)
IGCSE
29.
Grade (10)
J. 06 (19)
The diagrams show three experiments using dilute sulfuric acid. Three different powders
are added to the acid.
The mixtures are stirred.
Which test-tubes then contain Cu2+(aq) ions?
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
30. Three mixtures are made.
J. 06 (24)
1 C + Fe2O3
2 Cu + Fe2O3
3 Mg + Fe2O3
The mixtures are heated strongly.
Which of the elements C, Cu and Mg are reactive enough to reduce the iron oxide to iron?
A. C and Cu only
B. C and Mg only
C. Cu and Mg only
D. C, Cu and Mg
31. Which property do all metals have?
A. Their densities are low.
B. Their melting points are high.
C. They act as catalysts.
D. They conduct electricity.
J. 06 (25)
IGCSE
Grade (10)
32. Copper, iron and zinc are all used to make things.
Which of these three metals are also used in the form of alloys?
J. 06 (29)
33. Which diagram shows a common use of stainless steel?
J. 06 (27)
34.
J. 06 (29)
In experiments on rusting, some students are each given two metal objects to study.
One student set up his apparatus as shown.
Which objects rusted?
IGCSE
Grade (10)
35. The diagram shows the properties of four substances.
J. 07 (27)
Which one could be magnesium?
36. In ‘native’ copper, the element occurs as the metal, not as a compound.
J. 07 (28)
Gold is below copper in the reactivity series.
Which can be deduced about the properties of gold?
37.
J. 07 (30)
Stainless steel is used to make cutlery. Aluminium is used to make food containers
Which property do both metals have that makes them suitable for these uses?
A. They are good conductors of electricity.
B. They are good conductors of heat.
C. They are resistant to corrosion.
D. They are very strong.
IGCSE
Grade (10)
38. Which process takes place in the conversion of iron into steel?
J. 07 (31)
A. Basic oxides are removed.
B. Carbon is converted to carbon dioxide.
C. Iron is oxidised.
D. Iron oxide is reduced.
39. Which diagram best represents the structure of a solid alloy?
J. 08 (28)
40. Element E
J. 08 (29)
• forms an alloy;
• has a basic oxide;
• is below hydrogen in the reactivity series.
What is element E?
A. carbon
B. copper
C. sulfur
D. zinc
41. The position of metal X in the reactivity series is shown.
K
Na
Mg
Which statements about X and its oxide are correct?
Fe
J. 08 (30)
(H)
X
IGCSE
Grade (10)
42. The diagram shows a blast furnace used to extract iron from iron ore.
Why is limestone added to the furnace?
A. to cause the furnace to heat up
B. to change the ore into iron
C. to convert impurities in the ore into slag
D. to produce oxygen for the coke to burn
43. Which uses of the metals shown are both correct? J. 08 (32)
J. 08 (31)
IGCSE
Grade (10)
Paper 4
1.
J. 02 (1. a, c)
In 1886, the modern electrolytic process for the extraction of aluminium was discovered in
the USA by C. Hall.
(a) Before this discovery, the only method of extracting the metal was by displacement.
(i) Name a metal that can displace aluminium from aluminium chloride.
……...................................................................................................................................[1]
(ii) Write a word equation for this displacement reaction.
.....…...................................................................................................................................[1]
(iii) Complete the equation for the reaction.
AlCl3
+
......................
......................... +
..........................
[2]
(c) One property of aluminium is that it resists corrosion because it is covered with a layer
of its oxide.
(i)
Give one use of the metal that depends on this property.
…………..................................................................................................................[1]
(ii) Give another use of the metal that depends on a different property.
use....................................................................................................................................
property.......................................................................................................................... .[2]
2.
N. 02 (4. a, d)
For over 5000 years copper has been obtained by the reduction of its ores. More recently
the metal has been purified by electrolysis.
(a) Copper is used to make alloys.
(i) Give two other uses of copper.
………..................................................................................................................................[2]
IGCSE
Grade (10)
(ii) Alloys have similar structures to pure metals. Give a labelled diagram that shows
the structure of a typical alloy, such as brass.
[3]
(d) Copper is an unreactive metal. Its compounds are easily reduced to the metal or
decomposed to simpler compounds. Complete the following equations.
(i)
(ii)
...CuO
+
............................
Copper(II) hydroxide
(heat)
(iii) … Cu(NO3)2
(heat)
...Cu
+
............................
............................
............................
+
............................
............................ + ............................ + ............................
[4]
3.
J. 03 (1)
No one knows where iron was first isolated. It appeared in China, the Middle
East and in Africa. It was obtained by reducing iron ore with charcoal.
(a) Complete the following equation.
….. Fe2O3 + …. C
iron ore
charcoal
...................
+
........................
[2]
IGCSE
Grade (10)
(b) In 1705 Abraham Darby showed that iron ore could be reduced using coke in a blast
furnace
(i) The temperature in the furnace rises to 2000 °C. Write an equation for the
exothermic reaction that causes this high temperature.
…………..................................................................................................................................
(ii) In the furnace, the ore is reduced by carbon monoxide. Explain how this is formed.
…………..................................................................................................................................
…… …...................................................................................................................................
……………………………………………………………………………………………………….[3]
(c) The formation of slag removes an impurity in the ore. Write a word equation for the
formation of the slag.
……......................................................................................................................................[2]
IGCSE
Grade (10)
(d) Stainless steel is an alloy of iron. It contains iron, other metals and about 0.5% of
carbon.
(i) State a use of stainless steel.
………....................................................................................................................................
(ii) Name a metal, other than iron, in stainless steel.
…………...................................................................................................................................
(iii) The iron from the blast furnace is impure. It contains about 5% of carbon and other
impurities, such as silicon and phosphorus. Describe how the percentage of
carbon is reduced and the other impurities are removed.
…………...................................................................................................................................
…………..................................................................................................................................
............................................................................................................................................[ 6]
(e) One of the methods used to prevent iron or steel from rusting is to electroplate it with
another metal, such as tin. Complete the following.
The anode is made of ............................................... .
The cathode is made of ............................................. .
The electrolyte is a solution of ................................... .
4.
[3]
J. 03 (4. a)
Nitrogen dioxide, NO2, is a dark brown gas.
(a) Most metal nitrates decompose when heated to form the metal oxide, nitrogen dioxide
and oxygen.
(i) Write a symbol equation for the decomposition of lead(II) nitrate.
.. Pb(NO3)2
....................... + ....................... + ...................
[2]
(ii) Potassium nitrate does not form nitrogen dioxide on heating. Write the word
equation for its decomposition.
……...............................................................................................................................[1]
IGCSE
Grade (10)
5.
J. 04 (5. a)
(a) Copper has the structure of a typical metal. It has a lattice of positive ions and a “sea”
of mobile electrons. The lattice can accommodate ions of a different metal.
Give a different use of copper that depends on each of the following.
(i) the ability of the ions in the lattice to move past each other
……………………………………………………………………………………………………[1]
(ii) the presence of mobile electrons
……………………………………………………………………………………………………..[1]
(iii) the ability to accommodate ions of a different metal in the lattice
……………………………………………………………………………………………………[1]
6.
N. (4. a)
In the following list of ionic equations, the metals are in order of reactivity.
Zn
Sn
Hg
Ag
Zn2 +
Sn2+ +
Hg2+ +
Ag+ +
2e–
2e–
2e–
e–
reactivity of metals increases
(a) (i) In the space at the top of the series, write an ionic equation that includes a more
reactive metal.
(ii) Define oxidation in terms of electron transfer.
(iii) Explain why the positive ions are likely to be oxidising agents.
[1]
IGCSE
Grade (10)
(iv) Which positive ion(s) can oxidise mercury metal (Hg)?
7.
(a) (i) Write a symbol equation for the action of heat on zinc hydroxide.
N. 04 (7. a, b)
(ii) Describe what happens when solid sodium hydroxide is heated strongly.
(b) What would be observed when copper(II) nitrate is heated?
8.
J. 05 ( 2. a)
The following apparatus was used to measure the rate of the reaction between zinc and
iodine
IGCSE
Grade (10)
The mass of the zinc plate was measured every minute until the reaction was complete.
(a) Write an ionic equation for the redox reaction that occurred between zinc atoms and
iodine molecules.
……………………………………………………………………………………………………...
……………………………………………………………………………………………………[2]
9.
The position of aluminium in the reactivity series of metals is shown below.
J. 05 (6. b, d)
magnesium
aluminium
zinc
copper
(b) Aluminium reacts very slowly with aqueous copper(II) sulfate.
2Al(s) + 3CuSO4(aq)
(i)
Al2(SO4)3(aq)
+ 3Cu(s)
Which of the two metals has the greater tendency to form ions?
………………………………………………………………………………………………………[1]
(ii)
Describe what you would see when this reaction occurs.
………………………………………………………………………………………………………[1]
(iii) Explain why aluminium reacts so slowly.
…………………………………………………………………………………………………….[1]
(c) Predict the equations for the decomposition of the following aluminium compounds.
(i)
.. Al(OH)3
(ii) aluminium nitrate
…………………………….
+ ………………..
[2]
………………. +……..……….. +………………....
[2]
IGCSE
Grade (10)
10.
(b) The major ore of zinc is zinc blende, ZnS.
(i)
N. 05 (5. b, d)
Describe how zinc is extracted from zinc blende.
…………………………………………………………………………………………………..
..…………………………………………………………………………………………………[2]
(ii)
Give a use of zinc.
………………………………………………………………………………………………….[1]
(d) Both metals react with water.
(i) Write a word equation for the reaction of zinc and water and state the reaction
Conditions
word equation………………………………………………………………………..………. [1]
conditions………………………………………………………………………..…………… [2]
(ii) Write an equation for the reaction of strontium with water and give the reaction
condition.
equation ……………………………………………………………………………………..[2]
condition ……………………………………………………………………………………..[1]
11.
J. 06 (1. c, d, e)
(c) Iron is extracted in a blast furnace. The list below gives some of the substances used
or formed in the extraction.
carbon monoxide coke iron ore limestone slag
(i)
Which substance is a mineral containing largely calcium carbonate?
………………………………………………………………………………………………………[1]
(ii) Which substance is formed when impurities in the ore react with calcium oxide?
……………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(iii) Which substance is also called hematite?
……………………………………………………………………………………………………….[1]
(e) State two functions of the coke used in the blast furnace.
………………………………………………………………………………………………………
…………………………………………………………………………………………..……….[2]
(f) Most of the iron is converted into mild steel or stainless steel. Give one use for each.
mild steel……………………………..……………………………………………………………
stainless steel…………………………………………………………………………………… [2]
12.
Some reactions of metals W, X, Y and Z are given below.
J. 06 (2)
(a) Arrange these metals in order of reactivity.
most reactive
least reactive
…………………..
…………………..
…………………..
.……...................
[2]
IGCSE
Grade (10)
(b) Which of these metals could be
(i) magnesium,…………………………………………………………………………………. [1]
(iii) copper………………………………………………..………………………………………[1]
(c) The equation for the reaction of X with cold water is given below.
2X(s)
+ 2H2O(l)
2XOH(aq) + H2(g)
(i) Describe the test you would use to show that the gas evolved is hydrogen.
………………………………………………………………………………………………….[1]
(ii) How could you show that the water contained a compound of the type XOH?
…………………………………………………………………………………………………….
……………………………………………………………………………. ……………….…….[2]
(iii) In which group of the Periodic Table does metal X belong?
…………………………………………………………………………………………………….[1]
(iv) The ore of X is its chloride. Suggest how metal X could be extracted from its
chloride.
………………………………………………………………………………………………………
……………………………………………………………………………………………………..[2]
13.
(a) Titanium is produced by the reduction of its chloride. This is heated with
magnesium in an inert atmosphere of argon
TiCl4 + 2Mg →
J. 07 (5)
Ti + 2MgCl2
(i) Explain why it is necessary to use argon rather than air.
…………………………………………………………………………………………………..[1]
IGCSE
Grade (10)
(ii) Name another metal that would reduce titanium chloride to titanium.
…………………………………………………………………………………………………..[1]
(ii) Suggest how you could separate the metal, titanium, from the soluble salt
magnesium chloride.
………………………………………………………………………………………..………….
……………………………………………………………………………………………….… [2]
(b) Titanium is very resistant to corrosion. One of its uses is as an electrode in
the cathodic protection of large steel structures from rusting.
(i) Define oxidation in terms of electron transfer.
……………………………………………………………………………………………………[1]
(ii)
The steel oil rig is the cathode. Name the gas formed at this electrode.
………………………………………………………………………………………………….…….[1]
(iii) Name the two gases formed at the titanium anode.
……………………………..…… and ………………………………….
[2]
IGCSE
Grade (10)
(iv) Explain why the oil rig does not rust.
……………………………………………………………………………………………………….…
……………………………………………………………………………………………………..…[2]
(v) Another way of protecting steel from corrosion is sacrificial protection.
Give two differences between sacrificial protection and cathodic protection.
…………………………………………………………………………………………………………
……………………………………………………………………………………………….....…..[2]
14.
(d) Give an explanation for each of the following.
J. 07 (6. d)
(i) Aluminium is used extensively in the manufacture of aircraft.
……………………………………………………………………………………………………..….
……………………………………………………………………………………………………….[1]
(ii) Aluminium is used to make food containers.
……………………………………………………………………………………………………….…
……………………………………………………………………………………………………….[2]
(iii) Aluminium electricity cables have a steel core.
………………………………………………………………………………………………………[1]
IGCSE
Grade (10)
Paper 6
1.
J. 04 (6)
Copper oxide was reacted with hydrogen using the apparatus shown below.
(a) Indicate on the diagram with an arrow where the copper oxide is placed.
[1]
(b) The colour of the copper oxide would change from …………..… to …………..
[2]
(d) What is the purpose of the ice?
………………………………………………………………………………………………………[2]
IGCSE
Grade (10)
2.
N. 06 (2)
The diagram shows the rusting of a sample of iron filings.
(a) What colour are the rusty filings?
……………………………………………………………………………………………………….[1]
(b) Why does the water rise up the tube after rusting?
………………………………………………………………………………………………………………….[1]
(c) Calculate the percentage of air used in the rusting of the iron.
………………………………………………………………………………………………………
……………………………………………………………………………………….……………..[2]
(d) How would the results differ if pure oxygen was in the tube instead of air before
rusting?
……………………………………………………………………………………………………….[1]
IGCSE
Grade (10)
Topic 9
Chemical changes
• Production of energy
• Electricity from chemical reaction
IGCSE
Grade (10)
Paper 1
1. Samples of four different substances are added to separate volumes of water. J . 02 (14)
The temperature changes are measured.
For which substance does an exothermic reaction occur?
2.The diagram shows crystals of copper(II) sulfate, CuSO4. 5H2O, being heated.
The crystals change colour.
Which two terms describe this change?
A. endothermic and dehydration
B. endothermic and hydration
C. exothermic and dehydration
D. exothermic and hydration
J. 02 (15)
IGCSE
3.
Grade (10)
N. 02 (14)
A piece of magnesium is dropped into a test-tube containing dilute hydrochloric acid.
Why does the test-tube become warm?
A. Hydrogen is produced.
B. The magnesium neutralises the acid.
C. The reaction is endothermic.
D. The reaction is exothermic.
4. Potassium nitrate is a salt and dissolves in water in an endothermic process. N. 03 (15)
What happens to the temperature and pH of the water as the salt dissolves?
5. When it is used as a fuel, hydrogen combines with substance X.
What is X?
A. carbon
B. methane
C. nitrogen
D. oxygen
J. 04 (14)
IGCSE
Grade (10)
6. The table compares the strengths of the bonds for reactions of the type below. J. 04 (15)
X2
+
Y2
→
2XY
Which reaction is most exothermic?
7. Which process is endothermic? .
J. 04 (18)
A. adding water to anhydrous copper(II) sulfate
B. burning magnesium to make the oxide
C. heating water to make steam
D. neutralising acidic industrial waste
8. In which process does an endothermic change take place?
A. combustion
B. evaporation
C. filtration
D. neutralization
N. 04 (12)
IGCSE
9.
Grade (10)
J. 05 (14)
Which diagrams show a process in which an exothermic change is taking place?
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
10. Are hydrogen and uranium oxidised when used as a source of energy?
11. Which process is endothermic?
A. burning hydrogen to form water
B. condensing steam to water
J. 05 (15)
N. 05 (12)
IGCSE
Grade (10)
C. melting ice to form water
D. reacting sodium with water
12. The elements H2 and 235U are both used as fuels.
N. 05 (13)
In these processes, the reactions are …..1….. and …..2….. oxidised.
Which words correctly complete gaps 1 and 2?
13.
J. 06 (12)
The diagram shows an experiment in which magnesium oxide powder is added to dilute
hydrochloric acid
.
Which terms describe the experiment?
IGCSE
Grade (10)
14. Coal, methane and hydrogen are burned as fuels.
Which descriptions of this process are correct?
J. 06 (13)
15. Equations for two changes P and Q are shown.
P.
H2O(s)
→
H2O(l)
Q.
CH4(g)
+ 2O2(g) →
CO2(g)
N. 06 (14)
+
2H2O(l)
Which of these changes are exothermic?
16. The diagram shows a match.
By striking the match, a chemical reaction takes place.
J. 07 (14)
IGCSE
Grade (10)
Which statements about the chemical reaction are correct?
17. The diagram shows an experiment.
Which terms describe the experiment?
18. Charcoal and uranium are used as sources of energy. J. 08 (16)
Which of them are oxidised when used in this way?
J. 08 (15)
IGCSE
Grade (10)
Paper 3
1.
(f) The reactions of these metals with oxygen are exothermic.
2Ba(s) + O2(g)
→
J. 03 (5. f)
2BaO(s)
(i) Give an example of bond forming in this reaction.
………..................................................................................................................................
(ii) Explain using the idea of bond breaking and forming why this reaction is
exothermic.
………...................................................................................................................................
………................................................................................................................................[3]
2.
J. 04 (1. a)
It was reported from America that a turbine engine, the size of a button, might replace
batteries. The engine would be built from silicon which has suitable properties for this
purpose.
(a) (i) Why are batteries a convenient source of energy?
…………………………………………………………………………………………………….[1]
(ii) The engine will run on a small pack of jet fuel. What other chemical is needed to
IGCSE
Grade (10)
burn this fuel?
……………………………………………………………………………………………………..[1]
3.
(b) The following diagram shows a simple cell.
(i) Predict how the voltage of the cell would change if the tin electrode was replaced
with a silver one.
(ii) Which electrode would go into the solution as positive ions? Give a reason for your
choice.
N. 04 (4. b)
IGCSE
Grade (10)
(ii) State how you can predict the direction of the electron flow in cells of this type.
4.
N. 05 (7. c)
(c) (i) Complete the following table that describes the bond breaking and forming in the
reaction between nitrogen and hydrogen to form ammonia.
(iii) Explain, using the above data, why the forward reaction is exothermic.
………………………………………………………………………………………………………..
………………………………………………………………………………………………………[2]
5.
J. 06 (6. a, c, d)
(a) Exothermic reactions produce heat energy.
An important fuel is methane, natural gas. The equation for its combustion is as follows.
IGCSE
Grade (10)
CH4 + 2O2
→
CO2 + 2H2O
(i) In chemical reactions bonds are broken and new bonds are formed.
Using this reaction give an example of
a bond that is broken,……………………………………………………………………………….
a bond that is formed……………………………………………………………………………. [2]
(ii) Explain, using the idea of bonds forming and breaking, why this reaction is
exothermic, that is it produces heat energy.
………………………………………………………………………………………………………
………………………………………………………………………………………………………[2]
(c) Cell reactions are both exothermic and redox. They produce electrical energy as well
as heat energy.
(i) The diagram shows a simple cell
Which substance in this cell is the reductant and which ion is the oxidant?
Reductant……………………………………………………………………………………………..
oxidant ………………………………………………………………………………………….……[2]
IGCSE
(ii) How could the voltage of this cell be increased?
……………………………………………………………………………………………….……..[1]
(iii) What is the important large scale use, relating to iron and steel, of this type of cell
reaction?
……………………………………………………………………………………………………..[1]
(d) Cells can be set up with inert electrodes and the electrolytes as oxidant and reductant
The potassium manganate(VII) is the oxidant and the potassium iodide is the reductant.
(i)
Describe the colour change that would be observed in the left hand beaker.
Grade (10)
IGCSE
Grade (10)
…………………………………………………………………………………………………..……
………………………………………………………………………………………………………[2]
(ii)
Write an ionic equation for the reaction in the right hand beaker.
………………………………………………………………………………………………………
…………………………………………………………………………………………………….[2]
J.
Hydrogen reacts with the halogens to form hydrogen halides.
(a) Bond energy is the amount of energy, in kJ, that must be supplied (endothermic)
to break one mole of a bond.
Use the above data to show that the following reaction is exothermic.
…………………………………………………………………………………………………………….
……………………………………………………………………………………………………………
09 (7. a)
IGCSE
Grade (10)
…………………………………………………………………………………………………………….
…………………………………………………………………………………………………………….
[4]
Paper 6
1.
J. 04 (4)
A student investigated the temperature changes that occur when two compounds A and B,
react with hydrochloric acid. The apparatus below was used
IGCSE
Grade (10)
Experiment 1
By using a measuring cylinder, 30cm of hydrochloric acid was added to the plastic cup.
Use the thermometer diagram to record the initial temperature of the acid in the table. The
timer was started, and some of the solid A was added to the cup. Immediate effervescence
occurred. The mixture was stirred by moving the cup until the fizzing stopped.
More of A was then added and the student continued adding A in this way until all of solid A
had been added.
Use the thermometer diagrams to record the temperature of the mixture every half minute.
Experiment 2
Experiment 1 was repeated using solid B. Use the thermometer diagrams to record the
temperatures in the table.
Table of results
Experiment 1
IGCSE
(a) Plot the results from both experiments on the grid below. For each set of results draw
a smooth line graph. Indicate clearly which line represents Experiment 1 and which
line Experiment 2
[6]
Grade (10)
IGCSE
Grade (10)
IGCSE
Grade (10)
(b) From your graphs :
(i) Find the temperature of the reaction mixture after the hydrochloric acid had
reacted for 2 minutes 15 seconds with
solid A,………………………………………………………………………………………………
solid B……………………………………………………………………………………………. [2]
(iii)
What type of chemical reaction occurs when
solid A,…………………………………………………………………………………………….
solid B……………………………………………………………………………………………..
reacts with hydrochloric acid?
[2]
(c) Suggest what type of compound solids A and B are. Explain your answer
………………………………………………………………………………………………………
……………………………………………………………………………………………………[2]
(d) If the plastic cup and final reaction mixture are left for one hour, predict the temperature
at this time for
(i) solid A and hydrochloric acid,……………………………………………………………………
(ii) solid B and hydrochloric acid……………………………………………………………………
Explain your answers.
……………………………………………………………………………………………………….
………………………………………………………………………………………………………
……………………………………………………………………………………………………….
[3]
IGCSE
2.
Grade (10)
J. 06 (3)
A student carried out an experiment to measure the temperature changes during the
reaction of two solutions X and Y.
The instructions were as follows.
Leave the solutions to stand in the laboratory for one hour.
Pour 25 cm3 of solution X into a polystyrene cup and record its temperature.
Add 10 cm3 of solution Y and record the maximum temperature reached.
Repeat the experiment using 25 cm3 of solution X with different volumes of solution Y.
The results are shown in the table. Use the thermometer diagrams to record the
maximum temperatures reached.
IGCSE
Grade (10)
IGCSE
Grade (10)
(a) Why were the solutions left standing in the laboratory for about one hour before the
experiment?
………………………………………………………………………………………………………[1]
(b) What was the temperature in the laboratory?
……………………………………………………………………………………………………….[1]
(d) Why were the reactions carried out in a polystyrene cup rather than a glass container?
………………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(d) Plot the results on the grid. Draw two straight lines through the points, one for the
increasing temperatures and one for the decreasing temperatures.
(e) (i) Read from your graph the maximum temperature that could be reached in the
reaction.
…………………………………………………………………………………………………...[1]
(iii) Indicate on the graph where the two solutions completely react with each other. [1]
IGCSE
Grade (10)
(iv) What volume of solution Y exactly reacts with the 25 cm3 of solution X?
……………………………………………………………………………………………………[1]
(f) Circle which word correctly describes this chemical reaction.
endothermic
reversible
exothermic
[1]
IGCSE
Grade 10)
Topic 10
Chemical reactions
• Speed of reaction
• Reversible reaction
• Chemical equilibrium
IGCSE
Grade 10)
Paper 2
1.
Substance X does not react with dilute acid but substance Y does, forming a gaseous
product.
The graph shows the results of experiments with X, Y and dilute acid.
What do these results show about X?
2.
N. 02 (15)
An explosion in a coal mine was caused by the ignition of a mixture of methane and air.
Why did the mixture explode?
A. The heat absorbed by burning decreased the rate of burning.
B. The heat absorbed by burning increased the rate of burning.
C. The heat liberated by burning decreased the rate of burning.
D. The heat liberated by burning increased the rate of burning.
IGCSE
Grade 10)
3.
N. 02 (16)
The diagram shows an experiment to compare the speed of reaction when limestone chips
are added to acid.
In which test-tube is the reaction most rapid?
4.
J.03 (16)
When hydrated copper(II) sulfate is heated in the apparatus shown, solid X and liquid Y
are produced.
Which changes are noticed when liquid Y is added to cold solid X?
IGCSE
Grade 10)
5. A solution of hydrogen peroxide releases oxygen slowly at room temperature.
hydrogen peroxide
water + oxygen
The diagrams show the effect of adding blood to the solution.
J. 03 (17)
What could be the reason for the observed change?
A. Blood contains an enzyme.
B. Blood contains water.
C. The hydrogen peroxide becomes more concentrated.
D. The hydrogen peroxide is neutralised by blood.
6. A liquid X reacts with solid Y to form a gas.
J. 03 (18)
Which two diagrams show suitable methods for investigating the speed of the reaction?
A. 1 and 3
B. 1 and 4
C. 2 and 3
D. 2 and 4
IGCSE
Grade 10)
7. Two gases react as shown.
X2 + Y2
2XY
Reactants
product
When measured at the same temperature and pressure, what is the value of
N.03 (10)
A. 1/2
B. 1
C. 2
D. 4
8.
N. 03 (14)
The graph shows how the total volume of a gas given off from a reaction changes with time.
In which time interval is least gas given off?
9. The diagram shows an experiment
Which metal would fill the syringe with 100 cm3 of gas in the shortest time?
A. 5 g of copper
B. 5 g of iron
C. 5 g of magnesium
D. 5 g of zinc
N. 03
(18)
IGCSE
Grade 10)
10.
J. 04 (17)
In an experiment, a 2 g lump of zinc and 2 g of powdered zinc are added separately to
equal volumes of dilute sulfuric acid.
The solid line on the graph shows the volume of gas given off when the 2 g lump is used.
Which dotted line is obtained when the zinc is powdered?
11.
N. 04
In which experiment is the rate of reaction between hydrochloric acid and calcium
carbonate slowest?
(18)
IGCSE
Grade 10)
12.
J. 05 (2)
3
A student mixes 25 cm samples of dilute hydrochloric acid with different volumes of
aqueous sodium hydroxide.
Each time, the student measures the change in temperature to test if the reaction is
exothermic.
Which piece of apparatus is not needed?
13.
J. 05
In different experiments, 2 g of marble are added to 10 cm3 of hydrochloric acid.
In which tube is the reaction fastest?
(17)
14. The reaction between solution P and solution Q is exothermic.
N. 05 (2)
A student is told to test this statement by mixing equal volumes of the two solutions and
measuring the temperature change.
Which two pieces of apparatus should the student use?
A. balance and clock
B. balance and thermometer
C. pipette and clock
D. pipette and thermometer
IGCSE
Grade 10)
15. The diagram shows a speed of reaction experiment.
J. 06 (15)
Increasing the concentration of the acid and increasing the temperature both affect the
speed of reaction.
Which line of the table is correct?
16.
J. 07 (2)
o
A student investigates if, at 30 C, the concentration of acid affects how rapidly it reacts
with a known mass of magnesium.
The student has a beaker, concentrated acid, water and the apparatus below.
P. a balance
Q. a clock
R. a measuring cylinder
S. a thermometer
Which of these pieces of apparatus does the student use?
A. P, Q and R only
B. P, Q and S only
C. Q, R and S only
D. P, Q, R and S
IGCSE
Grade 10)
17.
J. 07 (17)
In an experiment using dilute acid and a metal, the speed at which hydrogen is released
is measured (curve X on graph).
The experiment is repeated but with one of the conditions changed (curve Y on graph).
Which changes in condition could result in curve Y?
18. The mass of a beaker and its contents is plotted against time.
N. 07 (16)
Which graph represents what happens when sodium carbonate reacts with an excess of
dilute hydrochloric acid in an open beaker?
IGCSE
19.
Grade 10)
J. 07 (17)
Which changes of condition slow down the reaction between magnesium and air?
1. heating the magnesium to a higher temperature
2. using a higher proportion of oxygen in the air
3. using magnesium ribbon instead of powdered magnesium
A. 1 only
B. 2 only
C. 3 only
D. 1, 2 and 3
20. A yellow precipitate is formed in the experiment shown.
How is the precipitate formed?
J. 08 (1)
A. Particles collide, diffuse and then react.
B. Particles collide, react and then diffuse.
C. Particles diffuse, collide and then react.
D. Particles diffuse, react and then collide
21. Magnesium reacts with acids to produce hydrogen gas.
Under which set of conditions is hydrogen formed the most slowly?
J. 08 (17)
IGCSE
Grade 10)
Paper 4
1.
J. 02 ((1. d)
(d) The graph shows how the rate of the exothermic reaction between aluminium and
hydrochloric acid varies with time.
(i)
Suggest a reason why the reaction goes slowly at first.
………...................................................................................................................... [1]
(ii)
Suggest two reasons for the increase in rate.
……….......................................................................................................................................
…………................................................................................................................................[2]
2.
J. 02 (2. b)
(b) Explain how the vine produces glucose by photosynthesis.
................................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
............................................................................................................................................[4]
IGCSE
Grade 10)
3.
(a) Sulfuric acid is made by the Contact Process.
2SO2(g) + O2(g)
N. 02 (1.a)
2SO3(g)
forward reaction is exothermic
(i) What are the reaction conditions for the Contact Process?
...............................................................................................................................................
………………………………………………………………………………………………………[3]
(ii) Would the yield of sulfur trioxide increase, decrease or stay the same when the
temperature is increased? Explain your answer.
.............................................................................................................................................
.............................................................................................................................................
...........................................................................................................................................[2]
4.
N. 02 (2. c)
(a) Aqueous hydrogen peroxide decomposes to form water and oxygen.
2H2O2(aq)
2H2O(l) +
O2(g)
This reaction is catalysed by manganese(IV) oxide
The following experiments were carried out to investigate the rate of this reaction.
A 0.1 g sample of manganese(IV) oxide was added to 20 cm3 of 0.2 M hydrogen
peroxide solution.
The volume of oxygen produced was measured every minute.
IGCSE
Grade 10)
The results of this experiment are shown on the graph.
(i)
How does the rate of reaction vary with time? Explain why the rate varies.
....................................................................................................................................................
................................................................................................................................................[3]
(ii) The following experiment was carried out at the same temperature.
0.1 g of manganese(IV) oxide and 20 cm3 of 0.4 M hydrogen peroxide
Sketch the curve for this experiment on the same grid.
(iii) How would the shape of the graph differ if only half the mass of catalyst had been
used in these experiments?
[2]
................................................................................................................................................
.................................................................................................................................................
.............................................................................................................................................[2]
IGCSE
Grade 10)
5.
N. 03 (3. c)
(c) A piece of paper is coated with a layer of silver (I) chloride . It is used in the following
experiment
(i) Explain why the silver (I) chloride that was not exposed to the light remained white but that
which exposed turned gray .
…………..……………………………………………………………………………………………..
……....……………………………………………………………………………………………..[2]
(ii) Write an equation for the reduction of the silver (I) ion.
……………….…………………………………………………………………………………………..
(iii) What difference would using a brighter light make ?
……........................................................................................................................................[1]
(iv) What is important application of this reaction?
……..…………………………………………………………………………………………………[1]
IGCSE
Grade 10)
6.
(c) The rate of this reaction can be measured using the following apparatus.
J. 04
(3. c)
The results of this experiment are shown on the graph below.
(i)
How does the rate of this reaction vary with time?
………………………………………………………………………………………………………..[1]
(ii)
Why does the rate vary?
…………………………………………………………………………………………………………..
…………………………………………………………………………………………………………….
…………………………………………………………………………………………………………[2]
(iii) The reaction is catalysed by copper powder. Sketch the graph for the catalysed
reaction on the same grid.
[2]
IGCSE
Grade 10)
(iii) Why is copper powder more effective as a catalyst than a single piece of copper?
………………………………………………………………………………………………………[1]
7.
N. 04 (1. c, d)
(c) Respiration and photosynthesis are two of the processes that determine the percentage
of oxygen and of carbon dioxide in the air.
(i) Name another process that changes the percentages of these two gases in air.
(ii)
The equation for photosynthesis is given below.
6CO2
+
6H2O
C6H12O6 + 6O2
This is an endothermic reaction.
Complete the reaction for respiration.
IGCSE
Grade 10)
(d) The rate of photosynthesis of pond weed can be measured using the following
experiment.
(i) Describe how you could show that the gas collected in this experiment is oxygen.
(ii) What measurements are needed to calculate the rate of this reaction?
(iii) What would be the effect, and why, of moving the apparatus further away from the
light?
IGCSE
Grade 10)
8.
N. 04 (3. a)
The simplest alcohol is methanol.
(a) It is manufactured by the following reversible reaction.
(i) Reversible reactions can come to equilibrium. Explain the term equilibrium.
(ii) At 400 oC, the percentage of methanol in the equilibrium mixture is lower than at
300 oC. Suggest an explanation.
(iii) Suggest two advantages of using high pressure for this reaction.
Give a reason for each advantage.
IGCSE
9.
Grade 10)
J. 05 (2. c)
The following apparatus was used to measure the rate of the reaction between zinc and
iodine.
(c) From the results of this experiment two graphs were plotted.
(i)
Which reagent iodine or zinc was in excess? Give a reason for your choice.
………………………………………………………………………………………………………[1]
(ii) Describe how the shape of graph 1 would change if 100cm3 of 0.05 mol/dm3 iodine
had been used.
……………………………………………………………………………………………………..
…………………………………………………………………………………………………….[2]
(iii) On graph 2, sketch the shape if the reaction had been carried out using 100 cm3 of
0.1 mol/dm3 iodine at 35 °C instead of at 25 °C.
[2]
IGCSE
Grade 10)
10.
N. 05 (3. A, b)
Reversible reactions can come to equilibrium. They have both a forward and a backward
reaction.
(a) When water is added to an acidic solution of bismuth(III) chloride, a white precipitate
forms and the mixture slowly goes cloudy.
(i)
Explain why the rate of the forward reaction decreases with time.
………………………………………………………………………………………………………….
………………………………………………….……………………………………………………..[2]
(ii)
Why does the rate of the backward reaction increase with time?
…………………………………………………………………………………………………………[1]
(iii) After some time why does the appearance of the mixture remain unchanged?
…………………………………………………………………………………………………………..
………………………………………………………………………………………………………….[2]
(iv) When a few drops of concentrated hydrochloric acid are added to the cloudy
mixture, it changes to a colourless solution. Suggest an explanation.
…………………………………………………………………………………………………………..
…………………………………………………………………………………………………………[2]
IGCSE
Grade 10)
(b) Both of the following reactions are reversible.
(i) Suggest a reason why an increase in pressure does not affect the position of
equilibrium for reaction 1.
………………………………………………………………………………………………………..[1]
(ii) What effect would an increase in pressure have on the position of equilibrium for
reaction 2? Give a reason for your answer.
……………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
(b) The equation for a stage of the Contact process is
The percentage of sulfur trioxide in the equilibrium mixture varies with temperature.
(i) How does the percentage of sulfur trioxide in the equilibrium mixture vary as the
temperature increases? Circle the correct answer.
increases
stays the same
decreases
[1]
(ii) Is the forward reaction in the equilibrium
2SO2
+
O2
2SO3
exothermic or endothermic? Give a reason for your choice.
…………………………………………………………………………………………………………
……………………………………………………………………………………………………… [2]
IGCSE
Grade 10)
(iii) Explain, mentioning both rate and percentage yield, why the temperature used in
the Contact process is 450°C.
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
11.
N. 06 (5. a)
Ammonia is manufactured by the Haber Process.
The forward reaction is exothermic.
(a) (i) What is the catalyst for this reaction?
…………………………………………………………………………………………………..[1]
(ii) Newer catalysts have been discovered for this process. Using these catalysts, the
operating temperature is lowered from 450°C to 400°C. What is the advantage of
using a lower temperature?
Explain your answer.
Advantage……………………………………………………………………………………………
Explanation…………………………………………………………………………………………
[2]
IGCSE
Grade 10)
12.
N. 06 (7)
The rate of a reaction depends on concentration of reactants, temperature and
possibly a catalyst or light.
(a) A piece of magnesium ribbon was added to 100 cm3 of 1.0 mol/dm3 hydrochloric
acid.
The hydrogen evolved was collected in a gas syringe and its volume measured
every 30 seconds.
In all the experiments mentioned in this question, the acid was in excess.
The results were plotted to give a graph.
IGCSE
Grade 10)
(i) The experiment was repeated. Two pieces of magnesium ribbon were added to
100 cm3 of 1.0 mol/dm3 hydrochloric acid. Sketch this graph on the same grid and
label it X.
[2]
(ii) The experiment was repeated using one piece of magnesium ribbon and 100 cm3
of 1.0 mol/dm3 ethanoic acid. Describe how the shape of this graph would differ
from the one given on the grid.
……………………………………………………………………………………………………
…………………………………………………………………………………………………..[2]
(b) Reaction rate increases when concentration or temperature is increased.
Using the idea of reacting particles, explain why;
increasing concentration increases reaction rate,
………………………………………………………………………………………………………….
………………………………………………………………………………………………………….
[2]
increasing temperature increases reaction rate.
………………………………………………………………………………………………………….
………………………………………………………………………………………………………….
[2]
(c) The rate of a photochemical reaction is affected by light. A reaction, in plants,
between carbon dioxide and water is photochemical.
(i)
Name the two products of this reaction.
……………………………………………………………………………………………………..[2]
(ii) This reaction will only occur in the presence of light and another chemical. Name
this chemical.
……………………………………………………………………………………………………..[1]
IGCSE
Grade 10)
13.
J. 08 (5. A, b, c)
Carbonyl chloride, COCl2, is a colourless gas. It is made by the following reaction.
(a) When the pressure on the equilibrium mixture is decreased, the position of
equilibrium moves to left.
(i) How does the concentration of each of the three chemicals change?
……………………………………………………………………………………………………..
………………………………………………………………………………………………….…..[2]
(ii) Explain why the position of equilibrium moves to left.
……………………………………………………………………………………………………..
………………………………………………………………………………………………………..[2]
(b) Using the information given with the equation, is the forward reaction exothermic
or endothermic? Give a reason for your choice.
………………………………………………………………………………………………………...
……………………………………………………………………………………………………….. [2]
(b) Carbonyl chloride reacts with water to form two acidic compounds.
Suggest which acidic compounds are formed.
1. …………………………………………………………………………………………………..
2. ………………………………………………………………………………………………..….[2]
IGCSE
Grade 10)
14.
Three of the factors that can influence the rate of a chemical reaction are:
J.08 (6a, b)
• physical state of the reactants
• light
• the presence of a catalyst
(a) The first recorded dust explosion was in a flour mill in Italy in 1785. Flour
contains carbohydrates. Explosions are very fast exothermic reactions.
(i) Use the collision theory to explain why the reaction between the particles of
flour and the oxygen in the air is very fast.
……………………………………………………………………………………………………
…………………………………………………………………………………………………… [2]
(ii)
Write a word equation for this exothermic reaction.
……………………………………………………………………………………………………..[1]
IGCSE
Grade 10)
16. The decomposition of silver(I) bromide is the basis of film photography.
The equation for this decomposition is:
This reaction is photochemical.
A piece of white paper was coated with silver(I) bromide and the following
experiment was carried out.
(b) Explain the results.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
………………………………………………………………………………………………………..
[3]
IGCSE
Grade 10)
Paper 6
1.
J. 02 (3)
The apparatus below was used to investigate the speed of the reaction between an excess
of dilute sulfuric acid and 4 cm of magnesium ribbon.
(a) (i) What is the purpose of the test-tube?
...........................................................................................................................................[1]
16 What is the purpose of the gas syringe?
..................................................................................................................................................[1]
(b) How was the reaction started?
..................................................................................................................................................[1]
(c) What does an excess of sulfuric acid mean?
...................................................................................................................................................[1]
IGCSE
The reaction produced hydrogen. The results obtained are shown in the table.
(d) Plot the results on the grid below and draw a smooth line graph.
Grade 10)
IGCSE
Grade 10)
(d) Which result appears to be incorrect? Why have you selected this result?
..................................................................................................................................................
………......................................................................................................................................[2]
(f) From the graph work out the volume of hydrogen produced after 30 seconds. Indicate
clearly on the grid how you used the graph.
................................................................................................................................................[2]
(g) Sketch on the grid the graph you would expect if the experiment were repeated using
2 cm of magnesium. Label this graph M.
2.
[1]
J. 03 (2)
A student carried out an experiment to investigate the speed of the reaction between sodium
thiosulfate and dilute hydrochloric acid.
Na2S2O3
+
2HCl
2NaCl
+
S
+
H2O
+ SO2
Experiment 1
By using a measuring cylinder, 50 cm3 of sodium thiosulfate solution was poured into a
100 cm3 beaker. The beaker was placed on a cross drawn on a piece of paper. 10 cm3 of
hydrochloric acid was added to the beaker and the timer started.
IGCSE
Grade 10)
The time was taken until the cross could not be seen. The time was recorded in the table.
Experiments 2, 3, 4 and 5
Experiment 1 was repeated using different volumes of sodium thiosulfate as shown in the
table. All experiments were carried out at 25 °C.
Table of results
(a) Why does the cross on the paper disappear?
…….........................................................................................................................................
…….......................................................................................................................................[2]
(b) Why was the total volume of solution kept constant?
……...........................................................................................................................................
……….....................................................................................................................................[1]
(c) In which order should the water, hydrochloric acid and sodium thiosulfate solution be
added to the beaker?
first .......................................................................................................................................
second .................................................................................................................................
last ......................................................................................................................................[1]
IGCSE
Grade 10)
(d) (i) Plot the results on the grid below. Draw a smooth line graph and label it 25 °C.
[5]
(ii) Sketch on the grid the graph you would expect if the experiments were repeated at
50 °C. Label this graph.
[2]
IGCSE
3.
Grade 10)
J. 06 (4)
A student investigates the speed of reaction when aqueous hydrogen peroxide breaks
down using a catalyst, manganese(IV) oxide. The catalyst remains unchanged at the of the
reaction. The apparatus was set up as shown in the diagram.
Experiment 1
By using a measuring cylinder, 20 cm3 of hydrogen peroxide solution was poured into a
conical flask. One spatula measure of manganese(IV) oxide was added to the flask, the
bung was quickly put in the flask and the timer started.
The volume of gas collected in the measuring cylinder at 10 seconds, 20 seconds and 30
seconds was measured.
The results are shown in the table below.
IGCSE
Grade 10)
Experiment 2
By using a measuring cylinder 15 cm3 of hydrogen peroxide was poured into the conical
flask. The instructions were repeated exactly as given for Experiment 1, but 5 cm3 of
distilled water was also added to the flask.
Use the diagrams to record your results in the table below
.
Experiment 3
Experiment 1 was repeated using 10 cm3 of hydrogen peroxide and 10 cm3 of distilled
water. Record your results in the table.
IGCSE
Grade 10)
Experiment 4
Experiment 1 was repeated using 5 cm3 of hydrogen peroxide and 15 cm3 of distilled water.
Record your results in the table.
(a) Plot your results on the grid for each Experiment. Draw 4 graphs and label each
clearly with the number of the Experiment.
(c) (i) Which Experiment has the fastest rate of reaction?
………………………………………………………………………………………………………[1]
(i) Explain, in terms of particles, why this Experiment has the fastest rate.
……………………………………………………………………………………………………………
…………………………………………………………………………………………………………[2]
IGCSE
Grade 10)
(d) (i) State two sources of error in the Experiments.
1…………………………………………………………………………………………………………
2…………………………………………………………………………………………………………
[2]
Suggest two improvements to reduce the sources of error in the Experiments.
1…………………………………………………………………………………………………………
2…………………………………………………………………………………………………………
[2]
(d) State a practical method you could use to prove that manganese(IV) oxide was a
catalyst in Experiment 1.
……………………………………………………………………………………………………………….
………………………………………………………………………………………………………………
IGCSE
4.
Grade 10)
J. 07 (6)
Hydrogen peroxide breaks down to form oxygen.
The volume of oxygen given off can be measured using the apparatus below.
Solids W and X both catalyse the breakdown of hydrogen peroxide. The syringe diagrams
show the volume of oxygen formed every 20 seconds using these catalysts at 25 °C.
IGCSE
(a) Use the gas syringe diagrams to complete the table.
Grade 10)
IGCSE
(b) Plot a graph to show each set of results. Clearly label the curves.
Grade 10)
IGCSE
Grade 10)
(c) Which solid is the better catalyst in this reaction? Give a reason for your choice.
Solid…………………………………………………………………………………………………..
Reason……………………………………………………………………………………………….
[2]
(d) Why is the final volume of oxygen the same in each experiment?
………………………………………………………………………………………………… [1]
(e) Sketch a line on the grid to show the shape of the graph you would expect if the
reaction with catalyst X was repeated at 40 °C.
[2]
IGCSE
Grade 10)
Topic 11
Air and water
• Purification of water supply
• Composition of air
• Manufacture of ammonia
• Fertilizers
• Air pollution
IGCSE
Grade 10)
Paper 2
1.
Air is a mixture of gases.
J. 02 (22)
Which substance is present in the ‘other gases’ and is also unreactive?
A. argon
B. carbon dioxide
C. hydrogen
D. water vapour
2. The diagram shows stages in producing drinking water.
J. 02 (29)
In which tank is chlorine added to the water?
3. Which gas is produced by the incomplete combustion of coal?
A carbon dioxide
B carbon monoxide
C nitrogen dioxide
D sulfur dioxide
J. 02 (30)
IGCSE
Grade 10)
4. The diagram shows the sources of energy a country uses to generate electricity. J. 02 (31)
What is the total percentage of fuels used which, when burned, could cause ‘acid rain’?
A. 20%
B. 80%
C. 90%
D. 100%
5. Which of the following does not need a supply of oxygen in use?
J. 02 (32)
A. breathing apparatus in hospitals
B. a fire extinguisher
C. an acetylene welding torch
D. a petrol engine
6.
J. 02 (33) / N. 07 ( 34)
To grow tomatoes, a fertiliser containing nitrogen, phosphorus and potassium is needed.
For a good yield, the fertiliser should contain a high percentage of potassium.
Which fertiliser is best for tomatoes?
7. Buildings made of calcium carbonate can react with ‘acid rain’.
Which gas is formed as a result of this?
A carbon dioxide
B carbon monoxide
C nitrogen dioxide
D sulfur dioxide
J. 02 (34)
IGCSE
Grade 10)
8. Which substance is used in the purification of water?
N. 02 (29)
A. calcium sulfate
B. carbon dioxide
C. chlorine
D. sodium chloride
9. Which pollutant, found in car exhaust fumes, does not come from the fuel?
N. 02 (30)
A. carbon monoxide
B. hydrocarbons
C. lead compounds
D. nitrogen oxides
N.02 (31)
Which place on the map is most likely to be producing large quantities of sulfur dioxide?
10.
11.
N. 02 (33)
Which two other compounds should be added to ammonium sulfate to make a complete
fertilizer NPK ?
A. KNO3, Na2HPO4
B. K2SO4, KNO3
C. NaCl, Ca3(PO4)2
D. NH4Cl, Na2HPO4
IGCSE
Grade 10)
12. Two uses of oxygen are
N. 02 (34) / N. 06 (33)
1 burning acetylene in welding,
2 helping the breathing of hospital patients.
Which of these uses form carbon dioxide
13. The pie-chart shows the composition of air.
What are the gases in parts 1, 2 and 3 of the pie-chart?
J. 03 (30)
IGCSE
Grade 10)
14. A steel works and a chemical works are built near to a city.
J. 03 (31)
The limestone buildings in the begin to crumble city
Which gas is most likely to cause this damage?
A. carbon dioxide
B. carbon monoxide
C. oxygen
D. sulfur dioxide
15. Which methods can be used to prevent the rusting of an iron girder of a bridge? J. 03 (32)
J. 03 (33)
A student heats a mixture of ammonium chloride and calcium hydroxide. She tests the gas
given off with damp red litmus paper.
What is the name of the gas and the final colour of the litmus paper?
16.
17.
J. 03 (34) / J. 06 (32)
A newspaper article claims that carbon dioxide is formed as follows.
1 during respiration
2 when calcium carbonate reacts with hydrochloric acid
3 when methane burns in air
Which statements are correct?
A. 1, 2 and 3
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
IGCSE
Grade 10)
18. The diagrams show the bonding in three covalent molecules.
N. 03 (9)
Which of these molecules combine to form ammonia?
A. 1 and 2
B. 1 and 3
C. 2 and 3
D. 1, 2 and 3
19. Which compound in polluted air can damage stonework and kill trees?
N. 03 (31)
A. carbon dioxide
B. carbon monoxide
C. lead compounds
D. sulfur dioxide
20. The diagram shows how water is purified.
N. 03 (29)
At which stage are bacteria in the water killed?
21. An NPK fertiliser contains three elements required for plant growth.
Which two compounds, when mixed, provide the three elements?
A. ammonium phosphate + potassium nitrate
B. ammonium sulfate + potassium nitrate
C. ammonium sulfate + sodium nitrate
D. sodium phosphate + potassium chloride
N. 03. (33)
IGCSE
Grade 10)
22. The diagram shows how oxygen is used in welding.
J. 04 (33)
What is gas X?
A. acetylene
B. argon
C. neon
D. nitrogen
23. The diagrams show the growth of four plants.
J. 04 (34)
Which element is acting as a fertiliser?
A. Cl
B. N
C. Na
D. S
IGCSE
Grade 10)
24. A candle is burned in a fixed volume of air.
How do the percentages (%) of carbon dioxide and oxygen change?
N. 04 (30)
25. Anhydrous calcium chloride is used as a drying agent.
An alkaline solution of pyrogallol absorbs oxygen and carbon dioxide.
Clean air is passed through the apparatus shown.
N. 04 (31)
Which gases are present in the air leaving the apparatus?
26. Which processes do not use oxygen? J. 05 (33)
1. burning natural gas
2. heating a room with an electric fire
3. welding apparatus
A. 1 only
B. 2 only
C. 3 only
D. 1, 2 and 3
IGCSE
Grade 10)
27. What is the purpose of the fine sand filter in the purification of the water?
N. 05 (28)
A. to allow particles to settle
B. to sort particles into layers
C. to trap large particles
D. to trap small particles
28.
N. 05 (29)
What is formed when ethane burns incompletely but not when it burns completely?
A. carbon dioxide
B. carbon monoxide
C. ethene
D. hydrogen
29. In which process is carbon dioxide not formed?
N. 05 (32)
A. blast furnace extraction of iron
B. burning of natural gas
C. heating lime
D. oxy-acetylene welding
30. The diagram shows stages in the purification of water.
Which stage uses chlorine?
J. 06 (28) / J. 09 (35)
IGCSE
Grade 10)
31. Which substance is not a pollutant of clean air?
J. 06 (30)
A argon
B carbon monoxide
C nitrogen dioxide
D sulfur dioxide
32. Which metallic element is needed in a complete fertiliser?
J. 06 (31)
A. calcium
B. magnesium
C. potassium
D. sodium
33. The diagram shows one stage in the manufacture of nitric acid from ammonia. N. 06 (22)
What could be the use of the platinum gauze in this process?
A. as a base
B. as a catalyst
C. as a filter
D. as a fuel
34. The diagram represents the composition of dry air.
Which part shows the percentage of nitrogen in the air?
N. 06 (29)
IGCSE
Grade 10)
35. The diagram shows some uses of water in the home.
N. 06 (30)
For which of these uses is it important for the water to have been purified?
A. 1 only
B. 2 only
C. 3 only
D. 1, 2 and 3
36. The listed pollutants are sometimes found in car exhaust fumes.
1. carbon monoxide
2. nitrogen oxides
3. sulfur dioxide
Which of these pollutants are products of the combustion of the fuel?
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
N. 06 (31)
IGCSE
Grade 10)
37. In which experiment does the limewater not turn milky?
J. 07 (20)
38. In which industrial process is the presence of water not essential?
J. 07 (32)
A. the electrolytic purification of copper
B. the production of ethanol from ethene
C. the production of ethanol by fermentation
D. the production of iron in the Blast Furnace
IGCSE
Grade 10)
39. The pie chart represents the composition of air.
J. 07 (33)
What is gas X?
A. carbon dioxide
B. hydrogen
C. nitrogen
D. oxygen
40. The diagrams show four sacks which a farmer has in his barn.
J. 08 (35)
Which sacks should be mixed to make a complete fertiliser, containing all the essential
elements needed by plants?
A. 1 and 2
B. 1 and 4
C. 2 and 3
D. 3 and 4
IGCSE
Grade 10)
Paper 4
1.
(b) One of the reasons for using hydrogen as a fuel is to reduce air pollution.
Petroleum powered vehicles are a major cause of air pollution.
J. 02 (3. B, c)
This pollution can be decreased by reactions of the type shown below.
2CO + 2NO
(i)
N2
+
2CO2
Where in a vehicle does this type of reaction occur?
………...................................................................................................................................[1]
(ii)
Explain how carbon monoxide is formed in the engine.
…………..................................................................................................................................
…….....................................................................................................................................[2]
(iii) Give a reason why the hydrogen-powered vehicle produces less pollution.
…………................................................................................................................................[1]
(c) Outline how hydrogen is manufactured from water.
……...........................................................................................................................................
……..........................................................................................................................................
………………………………………………………………………………………………………….[2]
2.
(c) Nitrogen dioxide and other oxides of nitrogen are formed in car engines.
(i)
J. 03 (4. c)
Explain how these oxides are formed.
…………..................................................................................................................................
…………...................................................................................................................................
IGCSE
Grade 10)
(ii) How are they removed from the exhaust gases?
…………...................................................................................................................................
..............................................................................................................................................[4]
3.
(b) About one third of this production of acid is used to make nitrogen and
phosphorus containing fertilisers.
J. 04 (2. b)
(i) Name the third element that is essential for plant growth and is present in most fertilisers.
……………………………………………………………………………………………………… [1]
(ii) Name a nitrogen-containing fertiliser that is manufactured from sulfuric acid.
………………………………………………………………………………………………………..[1]
(iii) Rock phosphate (calcium phosphate) is obtained by mining. It reacts with
concentrated sulfuric acid to form the fertiliser, superphosphate. Predict the
formula of each of these phosphates.
Fertilizer
ions
formula
calcium phosphate
Ca2+ and PO43–
…………………………………..
calcium superphosphate
Ca2+ and H2PO4–
………………………………….
[2]
4.
N. 04 (1. A, b)
(a) Two of the gases in air are nitrogen and oxygen. Name two other gases present in
unpolluted air.
…………………………………………………………………………………………………….[2]
IGCSE
Grade 10)
(b) Two common pollutants present in air are sulfur dioxide and lead compounds. State
the source and harmful effect of each.
sulfur dioxide
source………………………………………………………………………………………………….
harmful effect………………………………………………………………………………………….
[3]
lead compounds
source………………………………………………………………………………………………….
harmful effect…………………………………………………………………………………………
[2]
5.
N. 05 (7.a, b)
In 1909, Haber discovered that nitrogen and hydrogen would react to form ammonia. The
yield of ammonia was 8%.
(a) Describe how hydrogen is obtained for the modern process.
………………………………………………………………………………………………………
………………………………………………………………………………………………………[2]
(b) (i) What is the catalyst in the modern process?
………………………………………………………………………………………………………[1]
(ii) Explain why the modern process, which uses a lower temperature, has a higher
yield of 15%.
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….[2]
IGCSE
Grade 10)
6.
N. 06 (1)
Choose a gas from the following list to answer the questions below. Each gas may be used
once, more than once or not at all.
ammonia
argon
ethene
carbon dioxide
carbon monoxide
chlorine
hydrogen
nitrogen
oxygen
Which gas
(i) is a noble gas,……………………………………………………………………………………
(ii) is an acidic oxide,……………………………………………………………………………….
(iii) Can be polymerized……………………………………………………………………………
(iv) is the active component of air,………………………………………………………………..
(v) is used in the treatment of water,…………………………………………………………….
(vi) is a product of respiration?..............................................................................................
[5]
7.
Minimising air pollution is essential for health and for the environment.
N. 06 (4)
(a) Natural gas is methane.
(i) Write the equation for complete combustion of methane.
……………………………………………………………………………………………………….[2]
(ii) Explain why it is dangerous to use a gas fire in a poorly ventilated room.
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
(b) Low sulfur fuels are being introduced. Ordinary diesel contains 500 ppm of sulfur
but low sulfur diesel contains less than 50 ppm. Why is this an advantage to the
environment?
…………………………………………………………………………………………………….
……………………………………………………………………………………………………..[2]
IGCSE
Grade 10)
(c) Catalytic converters reduce pollution from motor vehicles, as shown in the following
diagram.
(i) What type of elements are the metals rhodium, platinum and palladium?
………………………………………………………………………………………………………..[1]
(ii) Rhodium catalyses the decomposition of the oxides of nitrogen.
2NO → N2 + O2
Two other pollutants are carbon monoxide and unburnt hydrocarbons. How are
they made into less harmful substances?
………………………………………………………………………………………………………...
………………………………………………………………………………………………………..[2]
8.
(c) Methylamine is a weak base like ammonia.
(i) Methylamine can neutralise acids.
2CH3NH2
+ H2SO4
N. 07 (6. c)
→
(CH3NH3)2 SO4
methyl ammonium sulfate
Write the equation for the reaction between methylamine and hydrochloric acid.
Name the salt formed.
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….[2]
(ii) When aqueous methylamine is added to aqueous iron(II) sulfate, a green
precipitate is formed. What would you see if iron(III) chloride solution had been
used instead of iron(II) sulfate?
……………………………………………………………………………………………………[1]
IGCSE
Grade (10)
Topic 12
Sulfur
IGCSE
Grade (10)
Paper 4
1.
J. 04 (2. a)
Sulfur is used to make sulfuric acid. In the UK, the annual production of the acid is about
2.5 million tonnes.
(a) The reactions in the manufacture of sulfuric acid by the Contact Process are
shown below.
(i) Give a large scale source of the element sulfur.
…………………………………………………………………………………………………….…[1]
(ii) State another use of sulfur dioxide.
……………………………………………………………………………………………………… [1]
(iii)How is sulfur changed into sulfur dioxide?
……………………………………………………………………………………………………… [1]
(iv)Name the catalyst used in reaction 2.
……………………………………………………………………………………………………… [1]
IGCSE
Grade (10)
(v) Reaction 2 is exothermic. Why is a catalyst, rather than a higher temperature, used
to increase the rate of this reversible reaction?
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
[2]
(vi) Write a word equation for reaction 3.
…………………………………………………………………………………………………………[1]
(vii) Write a symbol equation for reaction 4.
………………………………………………………………………………………………………….[1]
2.
J. 05 (4.
(c) Sulfuric acid is manufactured by the Contact Process. Sulfur dioxide is oxidised to
sulfur trioxide by oxygen.
2SO2
+ O2
2SO3
(i) Name the catalyst used in this reaction.
………………………………………………………………………………………………………….[1]
(ii) What temperature is used for this reaction?
………………………………………………………………………………….………………… .[1]
(iii) Describe how sulfur trioxide is changed into sulfuric acid.
………………………………………………………………………………………………………..[2]
3.
J. 06
(5. a)
Sulfuric acid is made by the Contact process in the following sequence of reactions.
Sulfur → sulfur dioxide → sulfur trioxide → sulfuric acid
(a) (i) How is sulfur dioxide made from sulfur?
……………………………………………………………..………………………………………….
[1]
IGCSE
Grade (10)
(ii) Sulfur dioxide has other uses.
Why is it used in the manufacture of paper?
……………………………………………………………………………………………………..…[1]
(iii) How does it preserve food?
……………………………………………………………………………………………….[1]
4.
N. 07 (4. a)
Zinc is extracted from zinc blende, ZnS.
(a) Zinc blende is heated in air to give zinc oxide and sulfur dioxide. Most of the sulfur
dioxide is used to make sulfur trioxide. This is used to manufacture sulfuric acid.
Some of the acid is used in the plant, but most of it is used to make fertilisers.
(i) Give another use of sulfur dioxide.
……………………………………………………………………………………………………….[1]
(ii) Describe how sulfur dioxide is converted into sulfur trioxide.
……………………………………………………………………………………………………….
………………………………………………………………………………………………………..
………………………………………………………………………………………………………...
[3]
(iii) Name a fertiliser made from sulfuric acid.
……………………………………………………………………………………………….[1]
IGCSE
Grade 10)
Topic 13
Carbonates
IGCSE
Grade 10)
Paper 2
1. Acidic waste gases from a factory are treated with substance X as shown.
J. 02 (35)
What is X?
A. polythene
B. slaked lime
C. vinegar
D. water
2. Lime is used to treat an industrial waste.
J. 02 (35)
Which pH change occurs in the treatment?
untreated waste
treated waste
A.
B.
C.
D.
acidic
alkaline
alkaline
neutral
neutral
acidic
neutral
acidic
IGCSE
3.
Grade 10)
J 03 (35)
The diagram shows how the pH of an industrial waste changes when substance X is
added to it.
What is substance X?
A. coal
B. lime
C. salt
D. water
4. Two processes are listed.
1. treating acidic soil with slaked lime
2. using limestone to extract iron
In which of these processes is carbon dioxide produced?
N. 03 (34)
IGCSE
Grade 10)
5. Compound X
J. 04 (36)
• does not dissolve in water,
• does not react with water,
• is used to control soil acidity.
What is X?
A. calcium carbonate
B. calcium chloride
C. calcium hydroxide
D. calcium oxide
6. What is formed when calcium carbonate is heated?
J. 04 (36)
A. calcium and carbon
B. calcium and carbon dioxide
C. calcium oxide and carbon
D. calcium oxide and carbon dioxide
7. A substance X is heated in an evaporating basin until there is no further change. J. 04 (36)
What could X be?
A. copper
B. copper(II) carbonate
C. copper(II) oxide
D. hydrated copper(II) sulfate
IGCSE
8.
Grade 10)
J. 04
(36)
A sample of acid rainwater (pH = 4) is passed down a glass column packed with marble
chippings(calcium carbonate).
The water coming from the bottom of the column is collected in a beaker.
The pH is now 6.
What causes the change in pH?
A. The acid has been filtered.
B. The acid has been neutralised.
C. The acid is made more concentrated.
D. The acid is precipitated
9. Dolomite is a rock that contains magnesium carbonate.
A piece of dolomite is heated strongly in air.
Which word equation correctly describes the reaction that takes place?
A. magnesium carbonate + water → magnesium hydroxide + carbon dioxide
B. magnesium carbonate + oxygen → magnesium oxide + carbon dioxide + water
C. magnesium carbonate + oxygen → magnesium oxide + water
D. magnesium carbonate → magnesium oxide + carbon dioxide
J. 05 (35)
IGCSE
Grade 10)
10.
J. 06 (34)
The diagram shows the pH values of the soil in X and Y, two parts of the garden of a house.
The house owner wishes to use lime to neutralise the soil in one part of the garden.
To which part should the lime be added, and why?
IGCSE
Grade 10)
11.The diagram shows a kiln used to heat limestone.
N. 06 (34)
What is the product and what waste gas is formed?
12. Which process is not exothermic?
A. burning a fossil fuel
B. obtaining lime from limestone
C. radioactive decay of 235U
D. reacting hydrogen with oxygen
13. What is the formula of limestone and of lime?
J. 07 (15)
IGCSE
Grade 10)
Paper 4
1.
J. 02 (2. a)
Fermentation of sugars is one method of making ethanol. Vines produce glucose by
photosynthesis. The glucose collects in the grapes which grow in clusters on the vine.
(a) Vines are attacked by a fungus that ruins the grapes. In 1882 it was discovered that
spraying the vines with Bordeaux mixture killed the fungus.
The fungicide, Bordeaux mixture, contains water, calcium hydroxide and copper(II)
sulfate.
(i)
Name the raw material from which calcium hydroxide is made.
………..................................................................................................................................[1]
2.
N. 03 ( 1. b ,c )
The table shows how the percentage of ammonia in the equilibrium mixture varies with
pressure at 600 °C.
(i)
Explain why the percentage of ammonia increases as the pressure increases.
…………....................................................................................................................................
…………..............................................................................................................................[2]
IGCSE
Grade 10)
(ii) How would the percentage of ammonia change if the measurements had been made
at a lower temperature?
Explain your answer.
.........................................................................................................................................
........................................................................................................................................
......................................................................................................................................[2]
(ii) State two of the reaction conditions used in the Haber Process.
.........................................................................................................................................
.....................................................................................................................................[2]
(c) Ammonia is a base.
(i)
Name a particle that an ammonia molecule can accept from an acid.
………...................................................................................................................................
(ii) Write an equation for ammonia acting as a base.
.................................................................................................................................[3]
3.
N. 06 (3. a ,c)
Calcium carbonate is an important raw material.
(a) Name a rock which is made up of calcium carbonate.
…………………………………………………………………………………………………….[1]
(b) When calcium carbonate is heated strongly, it decomposes.
CaCO3 →
CaO + CO2
(i) Calculate the relative formula mass of:
CaCO3…………………………………………………………………………………………….
CaO …………………………………………………………………………………………….[2]
IGCSE
Grade 10)
(ii) 7.00 kg of calcium oxide was formed. What mass of calcium carbonate was
heated?
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
(c) Calcium carbonate is used to control soil acidity.
(i) Why is it important to control soil acidity?
……………………………………………………………………………………………………….[1]
(ii) Both calcium carbonate, insoluble in water, and calcium oxide, slightly soluble, are
used to increase soil pH. Suggest two advantages of using calcium carbonate.
……………………………………………………………………………………………………
…………………………………………………………………………………………………….[2]
(iii) Give one use of calcium carbonate other than for making calcium oxide and
controlling soil pH.
…………………………………………………………………………………………………….. [1]
IGCSE
Grade (10)
Topic 14
Organic chemistry
IGCSE
Grade (10)
Paper 2
1. What is the structure of the product of the catalytic addition of steam to ethene? J. 02 (36)
2. Which process is used at an oil refinery?
J. 02 (37)
A. cracking
B. electrolysis
C. fermentation
D. neutralization
3. Which statement is correct both for methane and for ethane?
A. They are alcohols.
B. They are alkenes.
C. They are in the same homologous series.
D. They can undergo addition polymerisation.
J. 02 (38)
IGCSE
Grade (10)
4. Which reaction is an example of the cracking of an alkane?
J. 02 (39)
A. 3C2H4
B. C6H14
C. C6H12 + H2
D. C6H14
C6H12
6C + 7H2
C6H14
C2H4 + C4H10
5. In ripe fruit, the conversion of sugars into alcohol can occur naturally.
What is the name of this process?
J. 02 (40)
A. addition
B. cracking
C. fermentation
D. polymerization
6. The diagram shows an electric circuit.
For which two substances at X and Y does the bulb light up?
N. 02 (8)
IGCSE
Grade (10)
7. Butenedioic acid has the structure shown.
N. 02 (11)
What is the molecular formula of butenedioic acid?
A. CHO
B. C4H4O4
C. C6H4O2
8. Copper wires in an electricity cable are covered in plastic.
D. C6H4O6
N. 02 (13)
Why is plastic used?
A. It is an insulator.
B. It is a polymer.
C. It is hard.
D. It melts easily.
9. A compound Q has the structure shown.
What is the name of Q?
A. heptane
B. heptanoic acid
C. heptanol
D. heptene
N. 02 (36)
IGCSE
10.
Grade (10)
N. 02 (37)
A student sets up the apparatus shown to separate petroleum into its different liquid
parts.
Why does this method of separation work?
The liquids in petroleum have different
A. boiling points,
B. densities,
C. functional groups,
D. melting points.
11.
Which row in the table correctly shows properties of decane?
N. 02 (38)
IGCSE
Grade (10)
12. The equation shows the cracking of a hydrocarbon.
N. 02 (39)
Which compounds are unsaturated?
A. X only
B. Y only
C. X and Z
13. A student states that
D. Y and Z
N. 02 (40)
ethanol reacts with water to form beer and wine;
ethanol and water are used as solvents in industry.
Which of the underlined words are correct?
14. The diagram shows a model of an organic compound.
What is the name of this compound?
A. ethane
B. ethanoic acid
C. ethanol
D. ethane
J. 03 (36)
IGCSE
Grade (10)
15. Bitumen is a substance obtained from the fractional distillation of petroleum.
J. 03 (37)
What are the boiling points and the sizes of the molecules in bitumen?
16.
J. 03 (38)
Which hydrocarbons in the table are members of the same homologous series
A. 1 and 2
B. 1 and 3
C. 3 and 4
D. 1, 2, 3 and 4
IGCSE
Grade (10)
17. Which of the molecules shown can be polymerised?
J. 03 (39)
18.
Which conditions are necessary to ferment sugar into ethanol?
J. 03 (40)
IGCSE
19.
Grade (10)
Gas is released in all of the examples below.
J. 04 (35)
Which gas do they all produce?
A. carbon dioxide
B. hydrogen
C. methane
D. oxygen
20. Which compound contains three elements? .
J. 04 (37)
A. ethanol
B. ethene
C. methane
D. poly(ethene)
21. Four fractions obtained from crude oil (petroleum) are listed below.
Which fraction is paired with a correct use?
J. 04 (38)
IGCSE
Grade (10)
22. The structures of three compounds are shown.
J. 04 (39)
Why do these substances all belong to the same homologous series?
A. They all contain an even number of carbon atoms.
B. They all contain the same functional group.
C. They are all hydrocarbons.
D. They are all saturated.
23. The table shows some suggested reactions involving ethanol.
J. 04 (40)
Which suggestions about the reactants and products are correct?
24. Which substance is found in crude oil?
J. 05 (37)
A. bitumen
B. ethanol
C. ethanoic acid
D. poly(ethene)
25.
J. 05 (38)
Which statement about a family of organic compounds describes an homologous series?
All compounds in the family have the same
A. functional group.
B. physical properties.
C. relative molecular mass.
D. structural formula.
IGCSE
26.
Grade (10)
Which column describes ethane and which column describes ethene?
J. 05 (39)
A. 1 (ethane) and 2 (ethene)
B. 1 (ethane) and 3 (ethene)
C. 2 (ethene) and 3 (ethane)
D. 3 (ethane) and 4 (ethene)
27.
J. 05 (40)
Which of the products C12H24 and H2 could be formed by cracking dodecane, C12H26?
28. In the molecule shown, the two –OH groups are numbered.
Which of these –OH groups react with aqueous sodium hydroxide?
J. 06 (35)
IGCSE
Grade (10)
29. When a suitable catalyst is used, ethene reacts with steam.
What is the structure of the compound formed?
J. 06 (36)
30. The diagram shows the separation of crude oil into fractions.
J. 06 (37)
What could X, Y and Z represent?
IGCSE
31.
Which of the compounds shown are used as fuels?
Grade (10)
J. 06 (38)
32.
J. 06 (39)
Which set of diagrams shows three substances that are all in the same homologous series?
IGCSE
33.
The diagram shows the structure of a small molecule.
Grade (10)
J. 06 (40)
Which chain-like molecule is formed when these small molecules link together?
34. Students are asked to state
• the number of atoms in one molecule of ethanoic acid,
• the relative molecular mass, Mr, of this acid.
J. 07 (11)
Which line is correct?
35. Bromine and steam each react with ethene.
Which of these reactions need a catalyst?
J. 07 (37)
IGCSE
Grade (10)
36. What are formed when glucose is fermented?
J. 07 (38)
A. ethanol and carbon dioxide
B. ethanol and oxygen
C. ethene and carbon dioxide
D. ethene and oxygen
37.
J. 07 (39)
Which formula represents a compound that dissolves in water to form an acidic solution?
38.
Butane reacts as shown.
J. 07 (40)
What is this type of reaction?
A. combustion
B. cracking
C. polymerisation
D. reduction
39. The diagram shows a molecule of vinyl chloride (used to make pvc).
What is the formula of vinyl chloride?
A. CH2Cl3
B. CH3Cl2
C. C2HCl3
40. In which industrial process is water essential?
A. the production of aluminium from bauxite
B.the production of calcium oxide from limestone
C. the production of ethanol from ethene
D. the production of petrol from crude oil
J. 08 (11)
D. C2H3Cl
J. 08 (33)
IGCSE
Grade (10)
41.
J. 08 (34)
Some students are asked to suggest why acetylene, rather than ethanol, is the fuel used for
welding metals.
Two suggestions are
1 acetylene is a gas but ethanol is a liquid;
2 acetylene burns with a hotter flame.
Which suggestions are correct?
42. Cholesterol occurs naturally in the body.
J. 08 (37)
Its name indicates that it has the same functional group as
43. Which fuel is a mixture of hydrocarbons?
A. coal
B. methane
C. petroleum
D. wood
J. 08 (38)
IGCSE
Grade (10)
44.
In the diagram, which substance could be ethene?
J. 08 (39)
45.
Which properties do butane, propene and ethanol all have?
J. 08 (40)
IGCSE
Grade (10)
Paper 4
1.
J. 02 (2. C, d)
(c) The grapes are crushed to extract an aqueous solution of glucose. This solution is
fermented to make ethanol. Explain why each of the following is necessary.
(i)
yeast
...........................................................................................................................................[1]
(ii) an absence of oxygen
………...................................................................................................................................
……….................................................................................................................................[2]
(iii) an optimum temperature of about 35 °C
.............................................................................................................................................
...........................................................................................................................................[2]
(d) Plants can make esters as well as sugars. The formula of a typical ester is drawn below.
Deduce the names of the organic acid and of the alcohol from which the ester could
have been made.
organic acid .........................................................................................................................
alcohol................................................................................................................................[2]
IGCSE
Grade (10)
2.
J. 02 (3.a)
A major food retailer in the UK is going to distribute sandwiches using hydrogen-powered
vehicles.
(a) A sandwich contains three of the main constituents of food.
These constituents of food can all be hydrolyzed by boiling with acid or alkali.
(i) Complete the table.
[5]
(ii) What type of synthetic polymer contains the same linkage as
proteins, ...........................................................................................................................
fats? ..............................................................................................................................[2]
IGCSE
Grade (10)
(iii) Fats can be unsaturated or saturated. A small amount of a fat was dissolved in an
organic solvent. Describe how you could find out if this fat was saturated or
unsaturated.
reagent ................................................................................................................................
result if saturated ………......................................................................................................
result if unsaturated ............................................................................................................
.........................................................................................................................................[3]
3.
N. 02 (5)
Alkenes are unsaturated hydrocarbons. They show structural isomerism. Alkenes take part
in addition reactions and form polymers.
(a) Structural isomers have the same molecular formula but different structural formulae.
Give an example of structural isomerism.
molecular formula ..............................................................................................................
two structural formulae
[3]
(b) Ethene reacts with each of the following. Give the name and structural formula of each
product.
(i)
steam
name of product .............................................................................................................
structure of product
[2]
IGCSE
Grade (10)
(ii) hydrogen
name of product ..................................................................................................................
structure of product
[2]
(c) Alkenes polymerise by addition.
(i) Explain the term polymerise.
......................................................................................................................................
.....................................................................................................................................[2]
(ii) What is the difference between addition polymerisation and condensation
polymerisation?
......................................................................................................................................
....................................................................................................................................[2]
(iii) Poly(dichloroethene) is used extensively to package food. Draw its structure. The
structural formula of dichloroethene is drawn below.
. [2]
IGCSE
Grade (10)
(d) Steel may be coated with another metal, eg zinc or chromium, or with a polymer, eg
poly(chloroethene), to prevent rusting.
(i) Suggest a property of poly(chloroethene) that makes it suitable for this purpose.
….....................................................................................................................................[1]
(ii) Explain why the steel will rust when the protective coating of chromium or polymer
is broken.
.........................................................................................................................................[1]
(iii) When the protective layer of zinc is broken, the steel still does not rust.
Suggest an explanation.
............................................................................................................................................
...........................................................................................................................................
........................................................................................................................................[2]
J. 03 (3)
4.
Alkenes are unsaturated hydrocarbons. They undergo addition reactions.
(a) Two of the methods of making alkenes are cracking and the thermal decomposition of
chloroalkanes.
(i) Complete an equation for the cracking of the alkane, decane.
C10H22
Decane
............................
+
...............................
(ii) Propene can be made by the thermal decomposition of chloropropane.
Describe how chloropropane can be made from propane.
Reagents
propane and ..............................
Conditions
………………………………………… ................................................... [4]
IGCSE
Grade (10)
(b) The following alkenes are isomers.
(i)
Explain why they are isomers.
..............................................................................................................................................
............................................................................................................................................[2]
(ii) Give the name and structural formula of another hydrocarbon that is isomeric with
the above.
name ...................................................................................................................................
structural formula
[4]
(c) Give the name of the product when but-1-ene reacts with each of the following.
steam .....................................................................................................................................
hydrogen ................................................................................................................................
bromine ............................................................................................................................. [3]
(d) Alkenes can polymerise.
(i) Deduce the name and structural formula of the monomer from the structure of the
polymer.
name of monomer ....................................................................................................................
structural formula
[3]
IGCSE
Grade (10)
(ii) Draw the structure of the polymer formed from the following monomer.
[4]
(iii) Describe the pollution problems caused by the disposal of polymers in landfill sites
and by burning.
landfill sites ....................................................................................................................
....................................................................................................................................[2]
burning ...........................................................................................................................
......................................................................................................................................[1]
5.
J. 04 (6a, c)
In 2002, Swedish scientists found high levels of acrylamide in starchy foods that had been
cooked above 120 o C.
Acrylamide, which is thought to be a risk to human health, has the
following structure.
(a) (i) It readily polymerises to polyacrylamide. Draw the structure of this polymer.
[2]
IGCSE
Grade (10)
(ii) Starch is formed by polymerisation. It has a structure of the type shown below.
Name the monomer.
…………………………………………………………………………………………………… [1]
(iii) What are the differences between these two polymerisation reactions, one forming
polyacrylamide and the other starch?
……………………………………………………………………………………………………
…………………………………………………………………………………………………..[2]
(c) The structural formula of acrylic acid is shown below. It forms compounds called
acrylates.
(i) Acrylic acid reacts with ethanol to form the following compound.
Deduce the name of this compound. What type of organic compound is it?
Name……………………………………………………………………………………………………
type of compound………………………………………………………………………………….. [2]
(ii) Acrylic acid is an unsaturated compound. It will react with bromine. Describe the
colour change and draw the structural formula of the product of this addition
reaction.
colour change…………………………………………………………………………………….
structural formula of product
[2]
IGCSE
Grade (10)
6.
N. 04 (6)
Polymers are extensively used in food packaging. Poly(dichloroethene) is used because
gases can only diffuse through it very slowly. Polyesters have a high thermal stability and
food can be cooked in a polyester bag.
(a) (i) The structure of poly(dichloroethene) is given below.
IGCSE
Grade (10)
7.
N. 04 (8)
The alkenes are a homologous series of unsaturated hydrocarbons.
(a) The table below gives the names, formulae and boiling points of the first members
of the series.
IGCSE
Grade (10)
IGCSE
Grade (10)
IGCSE
Grade (10)
8.
J. 05 (3. A, c)
A South Korean chemist has discovered a cure for smelly socks. Small particles of silver are
attached to a polymer, poly(propene), and this is woven into the socks.
(a) (i) Give the structural formula of the monomer.
[1]
(ii) Draw the structural formula of the polymer.
[2]
(ii)
Suggest which one, monomer or polymer, will react with aqueous bromine and why?
…………………………………………………………………………………………………….
…………………………………………………………………………………………………….[2]
(c) The unpleasant smell is caused by carboxylic acids. Bacteria cause the fats on the skin
to be hydrolysed to these acids. Silver kills the bacteria and prevents the hydrolysis of
the fats.
(i) Fats are esters. Give the name and structural formula of an ester.
Name…………………………………………………………………………………………… [1]
structural formula
[1]
IGCSE
Grade (10)
(ii) Complete the word equation.
Ester +
water
carboxylic acid + ………………….
[1]
9.
J. 05 (4. b)
(b) Hydrogen sulfide gas which was escaping from nearby petroleum deposits was being
oxidised to sulfuric acid.
(i) Complete the equation for this reaction forming sulfuric acid.
H2S
+ …. O2
………………
[2]
(ii) Explain why all the hydrogen sulfide should be removed from the petroleum
before it is used as a fuel.
…………………………………………………………………………………………………[1]
10.
J. 05 (5a, b, c)
(iv) The synthetic polymer, nylon, has the same linkage as proteins. Draw the structural
formula of nylon.
[3]
(b) Enzymes called carbohydrases can hydrolyse complex carbohydrates to simple sugars
which can be represented as
Draw the structure of a complex carbohydrate.
[2]
IGCSE
Grade (10)
(c) Fermentation can be carried out in the apparatus drawn below. After a few days the
reaction stops. It has produced a 12% aqueous solution of ethanol.
(i) Complete the equation.
C6H12O6
Glucose
……………… + ……………………..
ethanol
carbon dioxide
[2]
(ii) Zymase catalyses the anaerobic respiration of glucose. Define the term respiration.
……………………………………………………………………………………………………
……………………………………………………………………………………………………[2]
(iii) Suggest a reason why the reaction stops after a few days.
…………………………………………………………………………………………………...[1]
(iv) Why is it essential that there is no oxygen in the flask?
…………………………………………………………………………………………………...[1]
(v) What technique is used to concentrate the aqueous ethanol?
…………………………………………………………………………………………………...[1]
IGCSE
Grade (10)
12.
(b) Complete the word equations for the reactions of ethanoic acid.
calcium + ethanoic acid
+
N. 05 (2. B, c)
……………………………
……………………………
……………………… + ethanoic acid
zinc ethanoate + water
[2]
(c) Write the symbol equation for the reaction between ethanoic acid and sodium
hydroxide.
……………………………………………………………………………………………………..[2]
13.
N. 05 (4)
The alcohols form a homologous series. The first member is methanol and the fourth is
butanol.
CH3- OH
Methanol
CH3- CH2-CH2 -CH2- OH
butanol
(a) (i) Give two general characteristics of a homologous series.
…………………………………………………………………………………………………...
……………………………………………………………………………………………………[2]
(ii)
Calculate the mass of one mole of the C8 alcohol.
………………………………………………………………………………………………………
……………………………………………………………………………………………………..[2]
(b) Give the name and structural formula of the third member of this series.
name ……………………………………………………………………………………………..[1]
structural formula
IGCSE
Grade (10)
(c) The structural formula of the fifth member, pentan-1-ol, is drawn below.
CH3- CH2-CH2 -CH2 -CH2 –OH
(i) Draw the structural formula of an isomer of this alcohol.
[1]
(ii) Predict the names of the product(s) formed when pentan-1-ol
• reacts with an excess of oxygen,
…………………….. and ……………………….
[1]
• is dehydrated to form an alkene,
……………………………………………………..
[1]
• is oxidised by acidified potassium dichromate(VI).
……………………………………………………..
[1]
14.
J. 06 (7)
The fractional distillation of crude oil usually produces large quantities of the heavier
fractions. The market demand is for the lighter fractions and for the more reactive alkenes.
The heavier fractions are cracked to form smaller alkanes and alkenes as in the following
example.
C4 H10 + C4H8
C8H18
octane
butane
butane
(a) (i) Write a different equation for the cracking of octane.
C8H18
………………… + ……………………
[1]
IGCSE
Grade (10)
(ii) The cracking of octane can produce isomers with the molecular formula C4H8.
Draw the structural formulae of two of these isomers.
[2]
(b) (i) Give the essential condition for the reaction between chlorine and butane.
……………………………………………………………………………………………………[1]
(ii) What type of reaction is this?
……………………………………………………………………………………………………[1]
(iii) This reaction produces a mixture of products. Give the names of two products
that contain four carbon atoms per molecule.
………………………….…….. and ……………………..………..
[2]
(c) Alkenes are more reactive than alkanes and are used to make a range of organic
chemicals. Propene, CH3–CH=CH2, is made by cracking. Give the structural formula
of the addition product when propene reacts with the following.
(i) water
[1]
(ii) bromine
[1]
IGCSE
Grade (10)
14.
The three types of food are carbohydrates, proteins and fats.
N. 06 (8)
(a) Aqueous starch is hydrolysed to maltose by the enzyme amylase.
The formula of maltose is:
Starch is hydrolysed by dilute sulphuric acid to glucose.
(i) What is an enzyme?
……………………………………………………………………………………………………[1]
(iii) Draw the structure of starch.
[1]
(iii) Name the technique that would show that the products of these two hydrolyses are
different.
…………………………………………………………………………………………………..[1]
(b) Proteins have the same linkage as nylon but there is more than one monomer in the
macromolecule.
(i) Draw the structure of a protein.
[2]
IGCSE
Grade (10)
(ii) What class of compound is formed by the hydrolysis of proteins?
……………………………………………………………………………………………………[1]
(c) Fats are esters. Some fats are saturated, others are unsaturated.
(i) Write the word equation for the preparation of the ester, propyl ethanoate.
……………………………………………………………………………………………………
……………………………………………………………………………………………………[2]
(iii) Deduce the structural formula of this ester showing each individual bond.
[2]
(iv) How could you distinguish between these two fats?
Fat 1 has the formula
Fat 2 has the formula
Test………………………………………………………………………………………………….
result with fat 1…………………………………………………………………………………….
result with fat 2…………………………………………………………………………………… [3]
IGCSE
Grade (10)
(iv) Both of these fats are hydrolysed by boiling with aqueous sodium hydroxide. What
type of compounds are formed?
………………………………..… and ……………………………….
15.
A major source of energy is the combustion of fossil fuels.
(a) (i) Name a solid fossil fuel.
[2]
J. 07 (1)
…………………………………………………………………………………………………...[1]
(ii) Name a gaseous fossil fuel.
…………………………………………………………………………………………………...[1]
(b) Petroleum is separated into more useful fractions by fractional distillation.
(i) Name two liquid fuels obtained from petroleum.
…………………………………….…….. and ……………………………………..
[2]
(ii) Name two other useful products obtained from petroleum that are not used as
fuels.
………………………………………….
and ……………………………………………. [2]
(iii) Give another mixture of liquids that is separated on an industrial scale by fractional
distillation.
………………………………………………………………………………………………….[1]
IGCSE
Grade (10)
16.
J. 07 (7. A, b, c)
Esters, fats and polyesters all contain the ester linkage.
(a) The structural formula of an ester is given below.
Name two chemicals that could be used to make this ester and draw their structural
formulae. Show all bonds.
Names………………………………………..…… and………………………………………….. [2]
structural formulae
[2]
(b) (i) Draw the structural formula of a polyester such as Terylene.
[2]
(iii)
Suggest a use for this polymer.
…………………………………………………………………………………………………[1]
IGCSE
Grade (10)
(c) Cooking products, fats and vegetable oils, are mixtures of saturated and unsaturated
esters.
The degree of unsaturation can be estimated by the following experiment. 4 drops of
the oil are dissolved in 5 cm3 of ethanol. Dilute bromine water is added a drop at a time
until the brown colour no longer disappears. Enough bromine has been added to the
sample to react with all the double bonds.
(i) Complete the one blank space in the table.
[1]
(ii) Complete the equation for bromine reacting with a double bond.
[2]
(iii) Using saturated fats in the diet is thought to be a major cause of heart disease.
Which of the products is the least likely to cause heart disease?
…………………………………………………………………………………………………………[1]
IGCSE
Grade (10)
17.
N. 07 (6. a, b, c)
The alcohols form a homologous series. The first four members are methanol, ethanol,
propan-1-ol and butan-1-ol.
(a) One characteristic of a homologous series is that the physical properties vary in a
predictable way. The table below gives the heats of combustion of the first three
alcohols.
(i) The minus sign indicates that there is less chemical energy in the products than in
the reactants. What form of energy is given out by the reaction?
…………………………………………………………………………………………………….[1]
(ii) Is the reaction exothermic or endothermic?
……………………………………………………………………………………………………..[1]
(iii) Complete the equation for the complete combustion of ethanol.
C2H5OH
+
O2
………………… +
…………………
[2]
IGCSE
Grade (10)
17.
J. 08 (6. c)
(c) The fermentation of glucose is catalysed by enzymes from yeast. Yeast is added to
aqueous glucose, the solution starts to bubble and becomes cloudy as more yeast
cells are formed.
C6H12O6(aq)
2C2H5OH(aq) + 2CO2(g)
The reaction is exothermic.
Eventually the fermentation stops when the concentration of ethanol is about 12%.
(i) What is an enzyme?
…………………………………………………………………………………………………...[1]
(ii) Pasteur said that fermentation was respiration in the absence of air. Suggest a
definition of respiration.
……………………………………………………………………………………………………
……………………………………………………………………………………………………[2]
(iii) On a large scale, the reaction mixture is cooled. Suggest a reason why this is
necessary.
…………………………………………………………………………………………………….[1]
(iii) Why does the fermentation stop? Suggest two reasons.
…………………………………………………………………………………………………...
…………………………………………………………………………………………………. [2]
(v) When the fermentation stops, there is a mixture of dilute aqueous ethanol and
yeast. Suggest a technique which could be used to remove the cloudiness due to
the yeast.
………………………………………………………………………………………………….[1]
Name a technique which will separate the ethanol from the ethanol / water mixture.
……………………………………………………………………………………………………[1]
IGCSE
Grade (10)
19.
J. 08 (8)
Large areas of the Amazon rain forest are cleared each year to grow soya beans. The trees
are cut down and burnt.
(a) Why do these activities increase the percentage of carbon dioxide in the atmosphere?
………………………………………………………………………………………………………
……………………………………………………………………………………………………..[2]
(b) Soya beans contain all three main food groups. Two of which are protein and
carbohydrate.
(i) What is the third group?
…………………………………………………………………………………………………[1]
(iii)
Draw the structural formula of a complex carbohydrate such as starch.
[3]
(iii) Compare the structure of a protein with that of a synthetic polyamide. The structure
of a typical protein is given below.
How are they similar?
……………………………………………………………………………………………………….
How are they different?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
[3]