Q1.
The chart shows the processes involved in the manufacture of nitric acid from
ammonia.
(a)
Complete the word equation for the reaction that takes place in the first reaction
vessel.
ammonia + ..............................
nitrogen monoxide + water
(1)
(b)
(i)
What is the use of the platinum gauze in the reaction vessel?
...........................................................................................................................
(1)
(ii)
At first, the platinum gauze is electrically heated. However, as the reaction
continues, no further heating is necessary.
Explain why.
...........................................................................................................................
(1)
Page 1
(c)
Explain why the heat exchanger is used.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(d)
To convert nitrogen monoxide into nitric acid, two further reactants are needed.
What are they?
............................................................ and ...............................................................
(1)
(e)
In an old method, nitrogen monoxide was produced from nitrogen instead of
ammonia.
The reaction was carried out at a high temperature (3000°C).
Suggest two reasons for this.
1 .................................................................................................................................
2 .................................................................................................................................
(2)
(f)
Complete the word equation below, to show how to make the fertiliser, ammonium
nitrate.
................................... + ..............................
ammonium nitrate + water
(2)
(Total 10 marks)
Q2.
(a)
Copper is a metal.
Explain how it conducts electricity.
Page 2
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Graphite is a non-metal.
Use the information to explain why graphite conducts electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 5 marks)
Q3.
(a)
The diagrams represent the atomic structures of two gases, hydrogen and
helium.
Page 3
Hydrogen gas is made up of diatomic molecules (molecules with two atoms).
Helium gas exists as single atoms.
(i)
How is a molecule of hydrogen formed from two hydrogen atoms?
(You may use a diagram as part of your answer)
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Why does helium exist only as single atoms?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Hydrogen combines with carbon to form methane.
Each molecule contains four hydrogen atoms strongly bonded to a carbon atom.
Explain why methane has a low boiling point.
.....................................................................................................................................
Page 4
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Q4.
The diagram shows electrolysis of sodium chloride solution.
(a)
Complete and balance these equations to show the reactions during electrolysis.
At the positive electrode
Cl–
–
e–
→
Cl2
At the negative electrode
Na
→
Na
(2)
(b)
Silver halides such as silver chloride and silver bromide are used in photography.
The equation shows a reaction to prepare a silver halide.
Page 5
Name and describe the products of this reaction, in words, as fully as you can.
product 1
.....................................................................................................................................
.....................................................................................................................................
product 2
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
Q5.
The chart shows the processes involved in the manufacture of nitric acid from
ammonia.
(a)
Complete the word equation for the reaction that takes place in the first reaction
vessel.
ammonia + ......................................
Page 6
nitrogen monoxide + water
(1)
(b)
What is the use of the platinum gauze in the reaction vessel?
.....................................................................................................................................
(1)
(c)
To convert nitrogen monoxide into nitric acid, two further reactants are needed.
What are they?
................................................................ and ............................................................
(1)
(d)
Complete the word equation below, to show how to make the fertiliser, ammonium
nitrate.
................................ + .........................
ammonium nitrate + water
(2)
(e)
Calculate the percentage of nitrogen in the fertiliser, ammonium nitrate NH4NO3.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 7 marks)
Q6.
A student does an experiment to examine the rate of reaction between magnesium
and dilute hydrochloric acid.
She adds 25 cm³ of the acid to a weighed amount of the metal.
The reaction produces hydrogen gas.
Magnesium + hydrochloric
acid
magnesium + hydrogen
chloride
Page 7
She collects the gas and measures the volume collected at one minute intervals.
All the metal reacted but there was some acid left unreacted.
Her results are shown on the graph.
(a)
The diagram shows part of the apparatus she used for the experiment.
Complete the diagram to show how the student could collect the hydrogen produced
and measure the volume after each minute.
(2)
(b)
(i)
When is the rate of reaction at its fastest?
Page 8
..........................................................................................................................
(1)
(ii)
State one way in which she could increase the rate of reaction.
..........................................................................................................................
(1)
(c)
(i)
What is the total volume of hydrogen collected in the experiment?
................................................................................................................... cm³
(1)
(ii)
State one way in which she could increase the final volume of hydrogen
collected.
..........................................................................................................................
(1)
(Total 6 marks)
Q7.
The diagram shows some magnesium ribbon burning.
Page 9
(a)
Choose words from the list to complete the sentences below.
electrical
an endothermic
heat
an exothermic
light
a neutralisation
kinetic
a reduction
When magnesium burns, it transfers .........................................................................
and ............................................................................ energy to the surroundings.
We say that it is .................................................................................. reaction.
(3)
(b)
Complete the word equation for the reaction.
magnesium + __________________________
magnesium oxide
(1)
(Total 4 marks)
Q8.
(a)
Write down the symbols for
lithium ................................................................................
fluorine ...............................................................................
(2)
(b)
The electronic structure of a lithium atom can be shown like this:
In a similar way, complete this diagram to show the electronic structure of a
fluorine atom.
Page 10
(1)
(c)
A lithium atom can lose one electron to form a lithium ion which can be written (2)+
A fluorine atom can gain one electron to form a fluoride ion.
Choose from the list the correct way to write the fluoride ion.
(2,6)+
(2,7)+
(2,7)-
(2,8)+
(2,8)–
Answer ..........................................
(2)
(Total 5 marks)
Q9.
This question is about the structure of atoms.
(a)
Choose words from the list to complete the sentences below.
electrons
ions
neutrons
protons
In an atom, the particles with a negative charge are called .....................................
Particles in the nucleus with no charge are called .....................................................
An atom has no overall charge because is has the same number of electrons and
....................................................................................................................................
(3)
(b)
Two isotopes of the element carbon are:
12
C
6
14
and
C
6
Complete the table of information for these two isotopes.
ATOMIC
NUMBER
MASS
NUMBER
NUMBER OF
PROTONS
Page 11
NUMBER OF
NEUTRONS
12
Isotope
C
6
6
12
Isotope
C
6
6
6
12
6
6
(2)
(Total 5 marks)
Q10.
(a)
The formula for the chemical compound magnesium sulphate is MgSO4.
Calculate the relative formula mass (Mr)of this compound. (Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Magnesium sulphate can be made from magnesium and dilute sulphuric acid.
This is the equation for the reaction.
Mg
+
H2SO4
→
MgSO4
+
H2
Calculate the mass of magnesium sulphate that would be obtained from 4g of
magnesium.
(Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 12
Answer..................................... g
(2)
(Total 4 marks)
Q11.
The diagrams show the giant structures of sodium chloride and diamond.
sodium chloride (melting point 801°C)
(a)
diamond (melting point 4800°C)
The equation shows how sodium choride could be formed.
Balance the equation.
Na
+
Cl2
→
Na Cl
(1)
(b)
By reference to the detailed structure of sodium chloride explain fully why:
(i)
sodium chloride has a quite high melting point,
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
solid sodium chloride melts when it is heated strongly,
Page 13
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
molten sodium chloride will conduct electricity.
...........................................................................................................................
...........................................................................................................................
(1)
(c)
By reference to the detailed structure of diamond, explain why the melting point of
diamond, is higher than that of sodium chloride.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 7 marks)
Q12.
Marble chips (calcium carbonate) react with dilute hydrochloric acid.
calcium
carbonate
+
hydrochloric
acid
→
calcium
chloride
+
carbon
dioxide
+
water
A student wanted to find out if the size of the marble chips made a difference to how fast
the reaction took place.
Page 14
(a)
What readings should she take?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
She repeated the experiment but this time used the same mass (10g) of large
marble chips.
In both experiments there was some marble left in the flask when the reaction
stopped.
These are the results of the two experiments.
TIME (minutes)
0
2
4
6
8
10
12
Loss in mass (g), using small chips
0.00 0.40 0.72 0.91 1.04
1.04
1.04
Loss in mass (g), using large chips
0.00 0.28 0.52 0.70 0.84
0.94
1.04
(i)
Explain the loss in mass in the two experiments.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
Page 15
(ii)
What difference does the size of the chips make?
...........................................................................................................................
...........................................................................................................................
(1)
(c)
A chemical reaction occurs when reacting particles collide with sufficient energy.
The reaction between marble and hydrochloric acid is faster if the acid is at a higher
temperature. Explain why.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
Q13.
The formula for the chemical compound magnesium sulphate is MgSO4.
Calculate the relative formula mass (Mr) of this compound. (Show your working.)
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 2 marks)
Q14.
(a)
The diagrams below show the electronic structure of a magnesium atom and
a magnesium ion.
Page 16
What is the charge on the magnesium ion? ...............................................................
(2)
(b)
Calcium bromide has the formula CaBr2.
What does this tell you about the ions in this compound?
....................................................................................................................................
....................................................................................................................................
(2)
(Total 4 marks)
Q15.
Calculate the formula mass (Mr), of the compound
calcium hydroxide, Ca (OH)2.
(Show your working)
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
(Total 3 marks)
Page 17
##
Here is a symbol equation, with state symbols, for a chemical reaction between
solutions of lead nitrate and potassium chloride.
Pb (NO3)2 (aq)
+
2 KCl (aq)
2KNO3 (aq)
+
PbCl2 (s)
The equation tells you the formulae of the two products of the reaction.
(a)
What are the names of the two products?
1 .................................................................................................................................
2 .................................................................................................................................
(2)
(b)
What else does the equation tell you about these products?
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 4 marks)
Q17.
The diagram shows one molecule of the compound ammonia.
Write down everything that the diagram tells you about each molecule of ammonia.
...............................................................................................................................................
...............................................................................................................................................
Page 18
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 4 marks)
##
Atoms of calcium, phosphorus and fluorine are represented below, each with its mass
number and proton number.
(a)
Use this information to complete the table.
CALCIUM
Number of protons in the nucleus
20
Number of neutrons in the nucleus
20
PHOSPHOROUS
Number of electrons
FLUORINE
9
16
15
9
(3)
(b)
Calcium and fluorine atoms can combine to form the compound calcium fluoride,
CaF2.
The fluoride ion is represented by F–.
(i)
Explain how the fluorine atom forms a fluoride ion.
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
How is the calcium ion represented?
Page 19
..........................................................................................................................
(2)
(c)
Phosphorus and fluorine form a covalent compound, phosphorus trifluoride.
Complete the sentences below which are about this compound.
Phosphorus trifluoride is made up of phosphorus and fluorine ................................
These are joined together by sharing pairs of ............................................... to form
phosphorus trifluoride ........................................................ .
(3)
(d)
(i)
Sodium chloride, an ionic compound, has a high melting point whereas
paraffin wax, a molecular compound, melts easily.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
Molten ionic compounds conduct electricity but molecular compounds are
non-conductors, even when liquid.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 14 marks)
Q19.
Here is a word equation for a chemical reaction.
Page 20
copper oxide
+
sulphuric acid
copper sulphate
+
water
Write down everything that the word equation tells you about the reaction.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 4 marks)
Q20.
The information on the Data Sheet will be helpful in answering this question.
(a)
Calculate the formula mass (Mr) of the compound iron (III) oxide, Fe2O3.
(Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Calculate the mass of iron produced when 32g of iron (III) oxide is completely
reduced by aluminium.
The reaction is shown in the symbol equation:
Fe2O3
+
2Al
→
2Fe
+
Al2O3
(Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Answer = ..................................... grams
(3)
(Total 6 marks)
Page 21
Q21.
The diagram shows the elements in Group 4 of the periodic table.
Carbon is a non‑metal and silicon is usually considered to be a non‑metal.
Tin and lead have all the usual properties of metals.
Germanium has these properties:
(a)
•
grey-white shiny solid
•
melting point 937°C
•
semi-conductor
•
reacts with chlorine to form the chloride (GeCl4) which is a liquid
molecular compound
•
germanium oxide reacts with acids to form a salt solution and water. It also
reacts with alkalis.
With reference to their structure, explain why tin and lead are good conductors
of electricity.
.....................................................................................................................................
Page 22
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Would you classify germanium as a metal or as a non-metal? Give your reasons.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q22.
You will find it helpful to use the information on the Data Sheet when answering this
question.
In the nucleus of an aluminium atom are:
and
(a)
13 protons
14 neutrons.
Complete these sentences.
(i)
The mass number of the aluminium atom is ...................................... .
(ii)
In an atom of aluminium there are ....................................... electrons.
(2)
Page 23
(b)
Why is an aluminium atom electrically neutral?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Complete the table for the element fluorine.
PARTICLE
NUMBER OF
PROTONS
Fluorine atom
9
Fluoride atom
NUMBER OF
NEUTRONS
NUMBER OF
ELECTRONS
9
10
(3)
(Total 7 marks)
Q23.
(a)
Balance these chemical equations.
(i)
H2 +
O2 →
H2O
(1)
(ii)
Al +
O2 →
Al2O3
(1)
(b)
Briefly explain why an unbalanced chemical equation cannot fully describe a
reaction.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
Page 24
(c)
Explain, as fully as you can, why a water molecule contains two hydrogen atoms but
a hydrogen chloride molecule contains only one.
(You may use a diagram in your answer if you wish).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
Q24.
(a)
The formula for ammonia is NH3. What does the formula tell you about each
molecule of ammonia?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Ammonia is used to make nitric acid (HNO3). Calculate the formula mass (Mr) for
nitric acid. (Show your working).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 25
.....................................................................................................................................
(3)
(Total 6 marks)
Q25.
When a solution of lead nitrate is added to a solution of sodium chloride, a white
precipitate of lead chloride is produced.
(a)
(i)
Why is a precipitate formed?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Complete and balance the equation for this precipitation reaction.
Pb+2(aq)
+
Cl–(aq) →
(3)
(b)
Complete the table below by writing in the name and formula of the precipitate
formed for each reaction. If there is no precipitate, write “no precipitate”.
Page 26
(5)
(Total 9 marks)
Q26.
The questions which follow refer to the element hydrogen.
(a)
Draw a diagram to show the bonding in one molecule of hydrogen.
(2)
(b)
The table gives information about two compounds which contain hydrogen.
Page 27
Use the information in the table to explain why it is difficult to classify hydrogen as a
metal or a non metal.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
Q27.
Sodium carbonate reacts with acids.
(i)
Complete the word equation.
sodium carbonate + hydrochloric acid → sodium chloride + ...................... + water
(1)
(ii)
Name the salt produced if sodium carbonate reacts with dilute nitric acid.
...........................................................................................................................
(1)
(Total 2 marks)
Page 28
Q28.
(a)
The chart shows the reactions of the metal calcium with water, oxygen and
dilute hydrochloric acid.
Name (i)
solution A .................................................................................................
(ii)
solid B .....................................................................................................
(iii)
gas C ........................................................................................................
(3)
(b)
The diagrams below show the electronic structure of an atom of calcium and an
atom of oxygen.
Describe fully what happens to its electrons when:
(i)
a calcium atom forms a calcium ion. State the charge on the calcium ion
formed.
...........................................................................................................................
Page 29
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
an oxygen atom forms an oxygen ion. State the charge on the oxygen ion
formed.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(c)
Calcium oxide is an ionic compound. Why do ionic compounds have high melting
points?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 11 marks)
Q29.
(a)
By reference to their structure, explain how the particles in a piece of metal
are held together and how the shape of the metal can be changed without it
breaking.
(You may use a diagram in your answer.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 30
(5)
(b)
Explain why metals are good conductors of electricity and suggest why this
conductivity increases across the periodic table from sodium to magnesium to
aluminium.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 9 marks)
Q30.
The diagrams show what happens when an acid is added to an alkali.
Page 31
(a)
What is present in the solution at stages 2 and 3 apart from universal indicator and
water?
(i)
At stage 2 .........................................................................................................
(ii)
At stage 3..........................................................................................................
(3)
(b)
Write an ionic equation to show how water is formed in this reaction and state the
sources of the ions.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q31.
Some students were investigating how fast hydrogen gas is released in the reaction
between magnesium and dilute hydrochloric acid.
To begin with they used 0.1 g of magnesium ribbon.
Next, they repeated the experiment using 0.1 g of magnesium powder.
In each case, they used enough acid to react with all the metal.
Page 32
(a)
Their results are shown on the graph below.
Hydrogen is produced in both the reactions.
Use the information on the graph to describe two other ways in which the two
reactions are similar.
1. .................................................................................................................................
.....................................................................................................................................
2. .................................................................................................................................
.....................................................................................................................................
(2)
(b)
Describe one way in which the reactions are different.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 3 marks)
Page 33
Q32.
The diagram below shows the electrolysis of sodium chloride solution, in the
laboratory.
(a)
Which gas forms at the negative electrode? ..............................................................
(1)
(b)
Explain why chlorine gas forms at the positive electrode.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
State one use of chlorine gas.
.....................................................................................................................................
(1)
(Total 4 marks)
Page 34
Q33.
The diagrams show what happens when an acid is added to an alkali.
(a)
What is present in the flask at stage 2, besides universal indicator and water?
.....................................................................................................................................
(1)
(b)
Write an ionic equation to show how water is formed in this reaction and state the
sources of the ions.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 4 marks)
Q34.
The two carbon atoms represented below are isotopes.
ISOTOPE 1
14
ISOTOPE 2
mass number
C
6
(a)
proton number
12
C
6
Describe two ways in which the isotopes are similar.
Page 35
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Describe as fully as you can one way in which they are different.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Q35.
Chlorine will combine with the non-metal element, carbon, to form this molecular
compound.
(a)
What is the type of bond in this molecule?
.....................................................................................................................................
(1)
(b)
Explain how these bonds are formed. (You may use a diagram).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 36
.....................................................................................................................................
(2)
(Total 3 marks)
Q36.
Magnesium oxide is a compound, made up of magnesium ions and oxide ions.
(a)
What is the charge on each magnesium ion? .............................................................
(1)
(b)
Explain how the magnesium ions get this charge.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Q37.
(a)
Iron powder is used in the manufacture of ammonia. Why is it used?
.....................................................................................................................................
Page 37
.....................................................................................................................................
(1)
(b)
Ammonia is manufactured from nitrogen and hydrogen. The equation for the
reaction between them is:
N2(g) + 3H2(g)
(i)
2NH3(g)
Which two raw materials are used to make the hydrogen?
.......................................................... and ........................................................
(1)
(ii)
Why does increasing the pressure increase the chance of molecules of
nitrogen reacting with molecules of hydrogen?
..........................................................................................................................
..........................................................................................................................
(1)
(iii)
Calculate the mass, in tonnes, of ammonia which could be produced from
560 tonnes of nitrogen.
The relative atomic masses are: H 1; N 14.
Show clearly how you get to your answer.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
Mass of ammonia = ............................................ tonnes
(3)
(Total 6 marks)
Q38.
Part of a reactivity series is:
Page 38
(a)
Carbon is used in blast furnaces to obtain iron and zinc from their oxides, but
electrolysis has to be used to obtain aluminium from its oxide.
Draw an arrow on the reactivity series above to show where carbon fits into the
series.
(1)
(b)
Predict the method of extraction used to obtain calcium from its ore and explain
your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
The formula for zinc oxide is ZnO. Write a balanced equation for the extraction of
zinc in the blast furnace.
.....................................................................................................................................
(2)
(Total 5 marks)
Q39.
(a)
The equation for the reaction that takes place when ammonium chloride is
heated is:
NH4Cl(s)
ammonium chloride
NH3(g)
+
ammonia
HCl (g)
hydrogen chloride
The diagram shows how a teacher demonstrated this reaction. The demonstration
was carried out in a fume cupboard.
Page 39
(i)
Apart from the gases normally in the atmosphere, which two gases would be
at X?
..................................................... and ...........................................................
(1)
(ii)
Name the white solid that has formed at Y.
..........................................................................................................................
(1)
(iii)
Why was the demonstration carried out in a fume cupboard?
..........................................................................................................................
..........................................................................................................................
(1)
(iv)
Complete the four spaces in the passage.
The chemical formula of ammonia is NH3. This shows that there is one atom of
.......................................... and three atoms of .................................. in each
......................................... of ammonia. These atoms are joined by bonds that
are formed by sharing pairs of electrons. This type of bond is called
Page 40
a ............................... bond.
(4)
(b)
Electrons, neutrons and protons are sub-atomic particles.
(i)
Complete the three spaces in the table.
Name of sub-atomic particle
Relative mass
Relative charge
...............................
1
+1
...............................
1
0
–1
...............................
(2)
(ii)
Which two sub-atomic particles are in the nucleus of an atom?
........................................................... and ...............................................
(1)
(Total 10 marks)
Q40.
The diagram represents the particles in a piece of reactive metal.
Page 41
The piece of reactive metal is added to dilute hydrochloric acid.
(a)
(i)
Which particle will probably react first?
Choose from:
•
•
•
a particle inside the piece;
a particle at the centre of a face;
a particle on one of the corners.
..........................................................................................................................
(1)
(ii)
Explain the reason for your choice.
..........................................................................................................................
..........................................................................................................................
(1)
(b)
The reaction can be speeded up by making changes to the hydrochloric acid or the
solid.
(i)
State two ways to speed up the reaction by changing the hydrochloric acid. In
each case explain in terms of particles why the reaction is faster.
1. ......................................................................................................................
Page 42
..........................................................................................................................
..........................................................................................................................
(2)
2. ......................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
What change can you make to the piece of solid to speed up the reaction?
Explain in terms of the particles why the reaction is able to speed up.
..........................................................................................................................
..........................................................................................................................
(2)
(Total 8 marks)
Q41.
Read the passage carefully and then answer the questions.
The electrolysis of acidified water
After a few drops of dilute sulphuric acid have been added to some distilled water, there will be three
types of ion in solution:
from the water,
H2O(l) → H+(aq) + OH–(aq)
from the acid,
H2SO4(aq) → 2H+(aq) + SO42– (aq)
When the electrodes (anode and cathode) in a circuit are put into the acidified water, the hydroxide
ions and the sulphate ions are both attracted to the electrode called the anode. However, it is harder
for the sulphate ions to give up their electrons than for the hydroxide ions to do this. So the
hydroxide ions are the ones which react and bubbles of oxygen are formed at the anode.
There are only hydrogen ions to be attracted towards the cathode and, when they get there, they
take up electrons to form hydrogen molecules.
From Chemistry Matters by Richard Hart, reproduced by permission of Oxford University Press
Even in a small volume of water acidified with dilute sulphuric acid there will be billions of
Page 43
ions. Some will be anions and some will be cations.
(i)
Name the ions in water acidified with dilute sulphuric acid.
.....................................................................................................................................
(1)
(ii)
Explain why only some of the ions are attracted to the anode.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(iii)
Balance the equation for the reaction of hydroxide ions at the anode.
4OH– → H2O + O2 + e–
(1)
(Total 4 marks)
Q42.
(a)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
(i)
Complete the spaces in the table to give information about both of the ions in
this lattice.
Page 44
Name of ion
Charge
.....................................................
.....................................................
.....................................................
.....................................................
(2)
(ii)
When it is solid, sodium chloride will not conduct electricity. However, molten
sodium chloride will conduct electricity. Explain this difference.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(iii)
Complete the sentence.
Sodium chloride conducts electricity when it is molten and when it is
..........................................................................................................................
(1)
(b)
The symbol for a calcium atom can be shown like this:
(i)
What is the mass number of this atom?
..........................................................................................................................
(1)
(ii)
What information is given by the mass number?
..........................................................................................................................
Page 45
..........................................................................................................................
(1)
(c)
Calcium burns in oxygen with a brick-red flame. The product is a white solid. It is
calcium oxide and its formula is CaO.
(i)
Balance the chemical equation for the reaction.
Ca(s) + O2(g) → CaO(s)
(1)
(ii)
Describe, in terms of electrons, what happens to a calcium atom when it
becomes a calcium ion.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 10 marks)
Q43.
Part of the Periodic Table showing the symbols for the first twenty elements is given
below.
(a)
Draw diagrams showing the arrangement of electrons (electronic structures) in:
(i)
an aluminium atom;
Page 46
(ii)
a chlorine atom.
(2)
(b)
(i)
Use electronic structures to help you show why the formula of sodium oxide is
Na2O.
(3)
(ii)
State why the formation of sodium ions is classified as an oxidation.
..........................................................................................................................
..........................................................................................................................
(1)
(Total 6 marks)
Q44.
(a)
Ammonium sulphate is made by the reaction:
2NH3(aq) + H2SO4(aq) →(NH4)2SO4(aq)
Page 47
(i)
Complete the three answers in the table.
Question
Answer
How many hydrogens are
there in
the formula of ammonium
sulphate?
..............................................................
What is the name of the
substance
with the formula NH3?
..............................................................
What is the name of the
substance
with the formula H2SO4?
..............................................................
(3)
(ii)
What is the main use for ammonium sulphate?
...........................................................................................................................
(1)
(iii)
A similar reaction is used to make ammonium nitrate. What is the name of the
acid which must be used?
...........................................................................................................................
(1)
(b)
NH3 is made by the reversible reaction:
N2(g) + 3H2(g)
(i)
2NH3(g)
Explain what the term reversible reaction means.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
Page 48
(ii)
What is the name of the raw material which is the source of nitrogen (N2)?
...........................................................................................................................
(1)
(iii)
Nitrogen is an element. Explain what the term element means.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks)
Q45.
The apparatus shown in the diagram was used to investigate the rate of reaction of
excess marble chips with dilute hydrochloric acid, HCl. Marble is calcium carbonate,
formula CaCO3. The salt formed is calcium chloride, CaCl2.
(a)
Write a balanced equation for the reaction.
....................................................................................................................................
....................................................................................................................................
(2)
Page 49
The following results were obtained from the experiment.
(b)
(i)
Time in
minutes
Reading on balance
in g
0.5
269.6
1.0
269.3
2.0
269.0
3.0
268.8
5.0
268.7
9.0
268.6
Plot the results and draw a graph on the axes below.
(3)
(ii)
Continue the graph you have drawn to show the expected reading after11
minutes.
(1)
Page 50
(iii)
On the axes above, sketch a graph of the result which would be obtained if in
a similar experiment the same mass of powdered marble was used instead of
marble chips.
(2)
(Total 8 marks)
Q46.
Ammonium nitrate and ammonium sulphate are used as fertilisers.
(i)
Which acid reacts with ammonia to form ammonium nitrate?
....................................................................................................................................
(1)
(ii)
Which acid reacts with ammonia to form ammonium sulphate?
Page 51
....................................................................................................................................
(1)
(iii)
The reactions in (i) and (ii) are both exothermic. How can you tell that a reaction is
exothermic?
....................................................................................................................................
....................................................................................................................................
(1)
(iv)
The reactions in (i) and (ii) are both examples of acid + base reactions. What is the
name of the chemical change which takes place in every acid + base reaction?
....................................................................................................................................
(1)
(Total 4 marks)
Q47.
The drawing shows a container of a compound called magnesium chloride.
(i)
How many elements are joined together to form magnesium chloride?
....................................................................................................................................
(1)
(ii)
Magnesium chloride is an ionic compound. What are the names of its ions?
Page 52
................................................. ions and ................................................. ions
(1)
(iii)
How many negative ions are there in the formula for magnesium chloride?
....................................................................................................................................
(1)
(iv)
Complete the sentence.
Ions are atoms, or groups of atoms, which have lost or gained
......................................... .
(1)
(v)
Suggest three properties which magnesium chloride has because it is an ionic
compound.
Property 1 ...................................................................................................................
....................................................................................................................................
Property 2 ..................................................................................................................
....................................................................................................................................
Property 3 ..................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
Q48.
(a)
Atoms are made of sub-atomic particles. Complete the six spaces in the
table.
Name of sub-atomic particle
Relative mass
.................................
Neutron
Relative charge
......................
.....................
Page 53
.......................
.................................
1
.......................
(3)
(b)
Complete the spaces in the sentences.
(i)
The atomic number of an atom is the number of ..................................... in its
nucleus and is equal to the number of ..................................................... if the
atom is not charged.
(1)
(ii)
The mass number of an atom is the total number of ................................. and
...................................... in its nucleus.
(1)
(c)
The table gives information about the atoms of three elements.
Number of electrons in:
Name of
element
Chemical
symbol
1st
shell
2nd
shell
3rd
shell
Fluorine
F
2
7
0
Neon
Ne
2
8
0
Sodium
Na
2
8
1
Two of these elements can react together to form a chemical compound.
(i)
What is the name and the formula of this compound?
Name ................................................... Formula ..........................................
(2)
(ii)
What type of bonding holds this compound together?
...........................................................................................................................
Page 54
(1)
(iii)
Explain, in terms of electron transfer, how the bonding occurs in this
compound.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks)
Q49.
The diagram shows the apparatus for an experiment. Hydrated copper sulphate
crystals were heated. They became anhydrous copper sulphate.
(a)
Name a suitable piece of equipment to heat tube A.
Page 55
.....................................................................................................................................
(1)
(b)
Use words from the box to complete the two spaces in the table. You may use each
word once or not at all.
black
blue
orange
red
purple
white
Name
Colour
Hydrated copper sulphate crystals
...................................................
Anhydrous copper sulphate
....................................................
(2)
(c)
What is the purpose of the ice and water in the beaker?
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
Drops of a clear, colourless liquid formed on the inside of tube B.
(i)
Name the liquid.
...........................................................................................................................
(1)
(ii)
Explain how the liquid came to be inside tube B.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(e)
Anhydrous copper sulphate can be turned into hydrated copper sulphate. What
would you need to add? Apart from the change in colour, what could you observe?
Page 56
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(f)
Copper sulphate can be made from black copper oxide by reacting it with an acid.
Name the acid.
.....................................................................................................................................
(1)
(Total 10 marks)
Q50.
The graph shows the volume of gas given off during an experiment using hydrogen
peroxide solution and manganese oxide.
Draw, on the axes above, a graph to show the result you would expect if the
volume of hydrogen peroxide solution had been the same, but it was twice as
concentrated.
(Total 3 marks)
Page 57
##
In this question you will need to use the following information:
Relative atomic masses: H 1; O 16; Mg 24.
The volume of one mole of any gas is 24 dm3 at room temperature and atmospheric pressure.
The diagram shows a chemical reaction taking place in a conical flask.
The balanced equation for this reaction is:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
(a)
Write a balanced ionic equation for this reaction.
....................................................................................................................................
(2)
(b)
Calculate the mass of magnesium required to produce 0.50 g of hydrogen. Show
clearly how you work out your final answer and give the unit.
.....................................................................................................................................
.....................................................................................................................................
Mass = ...............................
(2)
Page 58
(c)
(i)
Draw a diagram to show how the electrons are arranged in a hydrogen
molecule.
(1)
(ii)
What is the name of the type of chemical bond between the hydrogen atoms
in a hydrogen molecule?
...........................................................................................................................
(1)
(d)
The chemical formula for hydrogen peroxide is H2O2.
Calculate, to the nearest whole number, the percentage, by mass, of hydrogen in
hydrogen peroxide. Show clearly how you work out your answer.
....................................................................................................................................
....................................................................................................................................
Percentage = ................................. %
(2)
(Total 8 marks)
Q52.
Electrons, neutrons and protons are sub-atomic particles.
(a)
Complete the six spaces in the following table.
Name of sub-atomic particle
Relative mass
Relative charge
.......................................
1
........................................
Page 59
.......................................
........................................
.......................................
0
.........................................
(3)
(b)
An aluminium atom has 13 electrons. How are these arranged in shells around the
nucleus?
....................................................................................................................................
(1)
(c)
Chromium atoms have 24 protons and 28 neutrons.
(i)
How many electrons does each neutral chromium atom have?
...........................................................................................................................
(1)
(ii)
What is the mass number of chromium?
...........................................................................................................................
(1)
(d)
What change occurs to an atom which undergoes the process of reduction in a
chemical reaction?
....................................................................................................................................
....................................................................................................................................
(1)
(e)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
Page 60
Explain why the ions in this lattice stay in place.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 10 marks)
Q53.
Sea water is a good source of bromine. To obtain the bromine from the bromide ions
dissolved in sea water, it is displaced by reacting with chlorine. The bromine is removed
by blowing air through the mixture to carry away the bromine. Bromine and chlorine are
both in Group 7 of the Periodic Table.
Write a balanced ionic equation for the reaction between chlorine molecules and bromide
ions.
..............................................................................................................................................
.
(Total 3 marks)
Q54.
(a)
Every chemical element has a chemical symbol. Choose the correct chemical
symbols from the box and complete the three spaces in the table.
Page 61
C
Co
Cu
Fe
I
Ir
Zn
Zr
Name of element
Chemical symbol
Copper
....................................
Iron
....................................
Zinc
....................................
(3)
(b)
Give one use for each of the following metals. You should give a different use for
each metal.
Copper ......................................................................................................................
....................................................................................................................................
Iron ...........................................................................................................................
....................................................................................................................................
Zinc ...........................................................................................................................
....................................................................................................................................
(3)
(c)
Give four physical properties which metals usually have.
1. ................................................................................................................................
....................................................................................................................................
2. ................................................................................................................................
....................................................................................................................................
3. ................................................................................................................................
....................................................................................................................................
4. ................................................................................................................................
....................................................................................................................................
(4)
Page 62
(d)
Metals usually form ionic compounds. Give one property of an ionic compound.
....................................................................................................................................
....................................................................................................................................
(1)
(e)
The diagrams show two different atoms, atom A and atom B.
Atom A
(i)
Atom B
Complete the following sentence.
For these two atoms to become ions one ............................................ would
be transferred from atom ........... to atom ........... .
(1)
(ii)
Atom A and atom B are from different elements. How can you tell this from
their nuclei?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 13 marks)
Page 63
Q55.
Zinc powder normally reacts slowly with hydrochloric acid.
(a)
Balance the symbol equation for the reaction.
Zn
+
HCl
→
ZnC12
+
H2
(1)
The graph shows the results from a reaction of 1.0 g of zinc powder with 20 cm3 of
dilute hydrochloric acid. It gives off a gas and forms zinc chloride, ZnCl2. Some
unreacted zinc is left at the end.
(b)
Copper powder is a good catalyst for the reaction of zinc with hydrochloric acid.
(i)
A mixture of 10 cm3 of the same dilute hydrochloric acid and 1.0 g of copper
powder was added to 1.0 g of zinc powder. What is the maximum volume of
gas which could be given off?
.................................................................................................................... cm3
(1)
(ii)
Draw a graph, on the axes above, for an experiment where 20 cm3 of the
same dilute hydrochloric acid was added to 1.0 g of copper powder mixed with
1.0 g of zinc powder.
(2)
Page 64
(iii)
Give two other ways the reaction described in part (i) could be made to go
faster.
1. .......................................................................................................................
2. .......................................................................................................................
(2)
(c)
Copper powder can be formed by adding copper sulphate solution to the mixture of
zinc powder and acid.
(i)
Why does zinc react with copper sulphate solution to produce copper?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Write the word equation for the reaction.
...........................................................................................................................
(1)
(Total 8 marks)
Q56.
Many indigestion tablets contain calcium carbonate as their only active ingredient.
Calcium carbonate neutralises some of the hydrochloric acid in the stomach.
Two different indigestion tablets, X and Y, were separately reacted with excess
hydrochloric acid. The volume of gas given off in each reaction was measured every
minute.
The results are shown in the graph.
Page 65
(i)
Which tablet, X or Y, contained most calcium carbonate? ..............................
Explain the reason for your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(ii)
Which tablet, X or Y, reacted faster with hydrochloric acid?...........................
Explain the reason for your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(iii)
Explain the shape of the graph for tablet X between 3 and 5 minutes.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 3 marks)
Page 66
Q57.
The balanced symbol equation for the reaction is
H2 (g)
+
Cl2 (g) →
2HCl (g)
Starting with 2 g of hydrogen, what mass of hydrogen chloride would be produced?
(Relative atomic masses: H = 1; Cl = 35.5)
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Mass of hydrogen chloride = ...................................... g
(Total 3 marks)
Q58.
(i)
Complete the drawing to show the electron structure of a hydrogen fluoride
molecule. Draw electrons as dots or crosses.
(1)
(ii)
Explain why hydrogen fluoride is a gas at room temperature.
.....................................................................................................................................
Page 67
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Q59.
The flow diagram shows how to make ammonia and nitric acid from the nitrogen in
the air.
(a)
A fertiliser is made by neutralising ammonia with nitric acid. What is the name of
this fertiliser?
.....................................................................................................................................
(1)
(b)
In the flow diagram, why are two different catalysts used?
.....................................................................................................................................
.....................................................................................................................................
Page 68
(1)
(c)
What happens to catalysts at the end of a reaction?
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
Explain why catalysts are used in many industrial chemical reactions.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(e)
Explain, in terms of collisions between molecules, why a high pressure is used in
the reaction between nitrogen and hydrogen.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 7 marks)
Q60.
Ammonium chloride, NH4Cl, is made up of nitrogen, hydrogen and chlorine atoms.
(i)
Complete the table to show the number of atoms of each element present in NH4Cl.
Element
Number of atoms in NH4Cl
nitrogen
1
hydrogen
chlorine
Page 69
(1)
(ii)
Calculate the relative formula mass of ammonium chloride, NH4Cl.
(Relative atomic masses: H = 1, N = 14, Cl = 35.5)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Relative formula mass = .................................................
(2)
(Total 3 marks)
Q61.
(a)
A piece of lithium is placed on the surface of some water in a beaker.
Hydrogen is given off.
Lithium hydroxide is also formed.
Write a word equation for this reaction.
.....................................................................................................................................
(2)
(b)
The diagram shows the structure of a molecule of methane.
Write down everything that this diagram tells you about a methane molecule.
To gain full marks in this question you should write your ideas in good English. Put
them into a sensible order and use the correct scientific words.
.....................................................................................................................................
.....................................................................................................................................
Page 70
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
Q62.
Magnesium reacts with dilute sulphuric acid.
magnesium + sulphuric acid → magnesium sulphate + hydrogen
A student measured the volume of hydrogen given off every 10 seconds. The results are
shown on the graph.
(a)
The average rate of hydrogen production in the first 10 seconds is
Page 71
(60 cm3 ÷ 10 s) = 6 cm3/s.
(i)
Calculate the average rate of production of hydrogen between 30 seconds
and 50 seconds. Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Rate ............................... cm3/s
(3)
(ii)
Explain, as fully as you can, why the average rate between 30 and 50
seconds is different from the rate between 0 and 10 seconds.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
In industry, enzymes are used in both batch processes and continuous processes.
Give one reason why continuous processes are usually more profitable than batch
processes.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 6 marks)
Q63.
Hydrogen peroxide slowly decomposes into water and oxygen.
hydrogen peroxide → water + oxygen
The reaction can be speeded up by adding manganese dioxide.
(a)
(i)
What do we call a substance that speeds up a chemical reaction without
being changed itself?
Page 72
...........................................................................................................................
(1)
(ii)
Give two other ways of increasing the rate of this reaction.
1 ........................................................................................................................
2 ........................................................................................................................
(2)
(b)
The diagram shows how the rate of this reaction can be measured.
As the hydrogen peroxide decomposes, the mass of the flask and its contents
decreases.
Why does this decrease in mass take place?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
‘Iron tablets’ usually contain iron sulphate (FeSO4).
Q64.
(a)
This salt can be made by reacting iron with sulphuric acid.
Fe
+ H2SO4 → FeSO4
+ H2
Calculate the mass of iron sulphate that could be obtained from 4 g of iron.
(Relative atomic masses: Fe = 56, H = 1, O = 16, S = 32)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 73
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Mass of iron sulphate = ........................... g
(3)
(b)
Under different conditions, another type of iron sulphate may form.
Balance the symbol equation for this reaction.
Fe
+
H2SO4
→
Fe2(SO4)3
+
H2
(1)
(Total 4 marks)
Q65.
The diagram shows the structure of diamond.
(a)
To gain full marks for this question you should write your ideas in good English. Put
them into a sensible order and use the correct scientific words.
Explain, as fully as you can, why diamond has a high melting point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Page 74
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
The diagram below shows the outer electron shells of five carbon atoms in the giant
lattice of diamond.
Carbon atom C forms bonds with each of the carbon atoms W, X, Y and Z.
Draw the positions of all the electrons in the outer shells of each of carbon atoms
C, W, X, Y and Z.
(3)
(Total 6 marks)
Q66.
The flow diagram shows some stages in the manufacture of the fertiliser ammonium
nitrate (NH4NO3).
Page 75
(a)
The elements needed to make ammonia (NH3) are obtained from natural gas and
air. Which element is obtained from the air?
.....................................................................................................................................
(1)
(b)
The word equation for the formation of nitrogen monoxide is:
ammonia + oxygen →
nitrogen monoxide + water
The platinum catalyst needs to be heated only at the start of the reaction.
Suggest why.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Name the liquid A that reacts with nitrogen dioxide (NO2) to produce nitric acid
(HNO3).
.....................................................................................................................................
(1)
(d)
Describe how ammonium nitrate (NH4NO3) can be made from two of the products
shown in the flow diagram.
.....................................................................................................................................
.....................................................................................................................................
Page 76
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
Q67.
Marble is a rock that contains mainly calcium carbonate. This reacts with
hydrochloric acid.
calcium carbonate + hydrochloric acid → calcium chloride + water + carbon dioxide
The rate of this reaction was followed by measuring the mass of carbon dioxide formed.
Two 10 g samples of marble, A and B, were each reacted with 50 cm3 of dilute
hydrochloric acid, at different temperatures. The mass of carbon dioxide formed in each
reaction was recorded and plotted to produce the graph below.
Page 77
Each reaction stopped when no more carbon dioxide was formed.
In both experiments some marble was left unreacted when the reaction stopped.
(a)
Explain how you can tell which sample, A or B, reacted faster with the dilute
hydrochloric acid.
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
The faster rate of reaction was caused by using a higher temperature. Explain, in
terms of particles, why a higher temperature causes a faster rate of reaction.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 5 marks)
Page 78
Q68.
Calculate the percentage of iron in iron sulphate (FeSO4).
(Relative atomic masses: Fe = 56, O = 16, S = 32)
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Percentage of iron in iron sulphate = ..........................%
(Total 3 marks)
Q69.Hydrated copper sulphate is a blue solid. When it is heated, white solid anhydrous copper
sulphate is made. This is a reversible reaction.
hydrated copper sulphate
sulphate + water
(blue)
(a)
[+ heat energy]
anhydrous copper
(white)
To make the forward reaction work, the hydrated copper sulphate must be heated
all the time.
What type of reaction is this?
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Anhydrous copper sulphate can be used in a test for water. What two things will
happen when water is added to anhydrous copper sulphate?
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Page 79
Q70.
Hydrogen peroxide (H2O2) contains the same elements as water (H2O).
(a)
Name the hazard symbol shown by using the correct word from the box.
corrosive
flammable
oxidising
toxic
(1)
(b)
Hydrogen peroxide decomposes in the presence of a catalyst.
2H2O2(aq) → 2H2O(l) + O2(g)
(i)
Complete the word equation for this chemical reaction.
hydrogen peroxide → water + ................................
(1)
(ii)
What does a catalyst do to a chemical reaction?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 3 marks)
Page 80
Q71.
(a)
Magnesium burns in oxygen, forming magnesium oxide.
This equation represents the reaction.
Mg (s) + O2 (g) → MgO (s)
(i)
Balance the equation.
(1)
(ii)
Give the meaning of the state symbols (s) and (g).
(s) ..............................................
(g) ..............................................
(2)
(b)
Use the Formulae of Some Common Ions table on the Data Sheet to help you to
answer this question.
Magnesium also reacts with chlorine to form magnesium chloride.
Give the formula of magnesium chloride ..................................................................
(1)
(Total 4 marks)
Q72.
Iron is the most commonly used metal. Iron is extracted in a blast furnace from iron
oxide using carbon monoxide.
Fe2O3
(a)
+
3CO
→
Fe
+
3CO2
A sample of the ore haematite contains 70% iron oxide.
Calculate the amount of iron oxide in 2000 tonnes of haematite.
...............................................................................................................................
......
...............................................................................................................................
......
Amount of iron oxide = ......................................... tonnes
Page 81
(1)
(b)
Calculate the amount of iron that can be extracted from 2000 tonnes of haematite.
(Relative atomic masses: O = 16; Fe = 56)
...............................................................................................................................
.....
...............................................................................................................................
.....
...............................................................................................................................
.....
...............................................................................................................................
.....
...............................................................................................................................
.....
...............................................................................................................................
.....
Amount of iron = .................................................... tonnes
(4)
(Total 5 marks)
Q73.
The diagram shows a model of part of the giant lattice of a metal.
Page 82
(a)
Name particles X and Y.
X .....................................................
Y .....................................................
(2)
(b)
Explain, in terms of the giant structure above, why is it possible to bend a piece of
metal.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Page 83
Q74.
Calcium carbonate reacts with nitric acid to produce carbon dioxide.
CaCO3 + 2HNO3 → Ca(NO3)2 + H2O + CO2
A 10 g lump of calcium carbonate was reacted with 20 cm3 of dilute nitric acid. When the
reaction was finished, some of the calcium carbonate was left unreacted. The graph
shows the volume of carbon dioxide made in each minute for sixteen minutes.
(a)
The volume of carbon dioxide made in each minute decreases until it remains
steady
at 83 cm3.
Explain why.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(b)
Draw a graph line, on the axes above, for an experiment where 20 cm3 of the same
Page 84
dilute nitric acid was reacted with 10 g of powdered calcium carbonate.
(2)
(c)
Give one way of changing the rate of this reaction (other than using powdered
calcium carbonate).
....................................................................................................................................
....................................................................................................................................
(1)
(Total 5 marks)
Q75.
Calcium carbonate reacts with nitric acid to produce carbon dioxide.
CaCO3 + 2HNO3 → Ca(NO3)2 + H2O + CO2
A 10 g lump of calcium carbonate was reacted with 20 cm3 of dilute nitric acid. When the
reaction was finished, some of the calcium carbonate was left unreacted. The graph
shows the volume of carbon dioxide made in each minute for sixteen minutes.
Page 85
(a)
The volume of carbon dioxide made in each minute decreases until it remains
steady
at 83 cm3.
Explain why.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(b)
Draw a graph line, on the axes above, for an experiment where 20 cm3 of the same
dilute nitric acid was reacted with 10 g of powdered calcium carbonate.
(2)
(c)
Give one way of changing the rate of this reaction (other than using powdered
calcium carbonate).
....................................................................................................................................
....................................................................................................................................
(1)
(Total 5 marks)
Page 86
M1.
(a)
oxygen / O2
(do not allow air) for 1 mark
1
(b)
(i)
idea that
it is a catalyst / it increases the rate of reaction / lowers
activation energy
for 1 mark
1
(ii)
the reaction is exothermic or releases energy / heat
for 1 mark
1
(c)
idea that
•
hot gases from the first reaction vessel need to be cooled
•
incoming gases / ammonia / oxygen need to be heated
•
there is an energy saving / cost saving
any two for 1 mark each
2
(d)
water and oxygen
(need both)
(accept H2O and O2)
for 1 mark
1
(e)
idea that
•
breaking bonds / breaking up molecules requires a lot of
energy / reaction has a high activation energy
•
gives a better / faster rate of reaction
•
the reaction is endothermic / more energy needed to
break existing bonds than to form new ones
allow a higher temperature gives a greater yield / pushes
the equilibrium position to the right
any two for 1 mark each
2
Page 87
(f)
ammonia (solution) / ammonium hydroxide
(credit NH3
NH4OH)
nitric acid / HNO3
in any order for 1 mark each
2
[10]
M2.
(a)
•
idea that
copper has free electrons / electrons that move
throughout the structure
gains 1 mark
but
•
in copper, electrons from the highest (occupied) energy
level /outer shell, are
free / can move throughout the structure
gains 2 marks
2
(b)
idea that
•
in graphite, only three bonds are formed by each carbon atom
for 1 mark
•
one outer electron (per atom), free to move
for 1 mark
•
an electric current is a flow of (free) electrons*
for 1 mark
(* this mark to be given in either (a) or (b) but not in both)
3
[5]
M3.
(a)
(i)
idea that
•
two hydrogen atoms share one pair of electrons
•
linked by a covalent bond
Page 88
•
each then has two outer electrons / a full outer shell / two
•
electrons in the highest (occupied) energy level
(2 marks may be awarded for a correct electron diagram i.e. with electrons on
boundary of or within marked area).
any two for 1 mark each
2
(ii)
idea that
•
helium atoms do not give / take / share electrons / react
•
because the (outer) shell / orbit is full
or
•
highest (occupied) energy level is full
(but not just “contains two electrons”)
for 1 mark each
2
(b)
idea that
•
the (attractive) forces between molecules are weak
(not bonds between atoms)
•
so little energy is required / it is easy for molecules to escape from the liquid*
/ escape from other molecules*
(allow evaporate / change into a gas)
for 1 mark each
2
[6]
M4.
(a)
2Cl– – 2e– → Cl2
(allow unaltered LHS to produce ½ Cl2)
+
Na + e– → Na
(allow × 2 for all terms)
(credit candidates who point out that hydrogen / H2 is in fact produced)
for 1 mark each
2
Page 89
(b)
for product 1*, idea of a solid / precipitate or silver bromide
gains 1 mark
but solid / a precipitate of silver bromide
gains 2 marks
for product 2*, idea of aqueous / a solution / dissolved (in water) / or sodium nitrate
gains 1 mark
(do not allow liquid)
but aqueous / a solution / dissolved (in water) of sodium nitrate
(*do not credit formulae)
gains 2 marks
4
[6]
M5.
(a)
oxygen / O2 (do not allow air)
for 1 mark
1
(b)
idea that
(it is a) catalyst / it increases the rate of reaction
for 1 mark
1
(c)
water H2O and oxygen / O2 (need both) (in either order)
for 1 mark
1
(d)
ammonia / NH3 (do not allow ammonium)
(allow ammonium hydroxide / NH4OH or ammonia solution)
nitric acid / NHO3
in any order for 1 mark each
2
(e)
14 + 4 + 14 + 48 or Mr = 80
gains 1 mark
but
or 35%
gains 2 marks
2
[7]
Page 90
M6.
(a)
(must be possible for the gas to enter and displace the water) or other suitable
apparatus
•
apparatus to collect the gas correctly assembled
for 1 mark
•
calibrated collection vessel (award even if diagram is wrong)
for 1 mark
2
(b)
(i)
at the start / in the first 1/2 minutes (or any time within this range)
for 1 mark
1
(ii)
increase the temperature / use smaller pieces of metal /
use more metal / increase the surface area of the metal /
add a catalyst / shake the flask / increase the concentration /
strength of the acid
for 1 mark
1
(c)
(i)
48
for 1 mark
1
(ii)
increase the amount of magnesium used
for 1 mark
(do not allow increase the amount of acid used)
1
[6]
M7.
(a)
heat
light
an exothermic
in any order for 1 mark each
3
Page 91
(b)
oxygen / O2
for 1 mark
1
[4]
M8.
(a)
lithium = Li
(ignore mass / atomic numbers)
fluorine = F (do not allow if case is incorrect)
for 1 mark each
2
(b)
(allow ● or o for electrons)
(allow any positions for the seven electrons added provided
they are on the outer ring)
for 1 mark
1
(c)
(2,8)+ or (2,7)–
(brackets not required) gains 1 mark
but (2,8)–
gains 2 marks
2
[5]
M9.
(a)
electrons
neutrons
protons
for 1 mark each
3
(b)
mass number
no. of neutrons
14
8
for 1 mark each
2
[5]
Page 92
M10.
(a)
Mg S O4
24 + 32 + 16 (×4) or 64 / evidence of all Ar’s
gains 1 mark
but (Mr) = 120
gains 2 marks
2
(b)
evidence that 24(g) magnesium would produce 120(g) mapesiurn sulphate
gains 1 mark
or correct scaling by 1/6
but 20(g) magnesium sulphate
gains 2 marks
[credit error carried forward from (a) with full marks in (b)]
2
[4]
M11.
(a)
2 Na + Cl2 → 2 NaCl
allow 2 Na+ Cl– for 1 mark
(allow Na + ½Cl2 → Na Cl)
1
(b)
(i)
idea that
•
it has strong (attractive) forces/bonds between ions / charged
particles
for 1 mark
(not ‘..it has a rigid structure’- this defines a solid or ‘...particles
close together’ – they are in a liquid)
1
(ii)
ideas that
•
there is increased vibration of ions / particles on heating
Page 93
•
ions have sufficient energy to overcome attractive forces / to
break out of the
•
rigid structure / to move about
(must be in terms of increased energy of particles lions)
each for 1 mark
2
(iii)
•
ions can go to electrodes / ions are free to move
for 1 mark
[do not credit ‘ions carry charges’]
1
(c)
ideas that
•
it has stronger attractive forces between atoms/particles (not ‘ions’)
•
each carbon atom forms covalent bonds with neighbouring atoms
each for 1 mark
2
[7]
M12.
(a)
ideas that
•
ref to read the balance / read the mass / weight
•
ref to read the stop clock / read the time
•
‘readings’ taken at the beginning and end / at regular intervals
for 1 mark each
2
(b)
(i)
•
(ii)
•
•
loss of carbon dioxide (from the flask) }
smaller chips give faster reaction / reaction } mark as a whole
finishes quicker /dissolved faster [or reverse] }
smaller chips have a larger surface area }
any 2 for 1 mark each
[Allow converse answers]
2
Page 94
(c)
ideas that
•
heating increases the speed / energy / vibration of the (acid)
particles / marble particles
•
(acid) particles collide (with marble chips / (particles)) more
frequently / more likely to collide
•
reacting particles collide with greater energy / collide faster
•
so particles more likely to react [do not accept ‘react faster’]
[Accept ‘atoms’, ‘molecules’ or ‘ions’ instead of ‘particles’ in this question]
any three for 1 mark each
3
[7]
M13.
Mg
S
O4
24 + 32 + 16 (×4) or 64 / evidence of all Ar’s correct [so 24 + 32 + 16 1 mark]
gains 1 mark
but (Mr) = 120
No ECF
gains 2 marks
[2]
M14.
(a)
positive / + / 2
gains 1 mark
but 2+ / ++ / +2
gains 2 marks
2
(b)
Ideas that: 2
Ca2+
Br- [Do not disqualify for "bromine" ions]
Ions / They are in the ratio 1:2
any two for 1 mark each
2
Page 95
[4]
M15.
Ca = 40
(OH)2 = (16 + 1)2 or 34
gain 1 mark each
but
Mr = 74
gains 3 marks
[3]
M16.
(a)
lead chloride
} in any order
potassium nitrate }
for 1 mark each
2
(b)
lead chloride is solid / a precipitate
potassium nitrate is aqueous / in solution / dissolves in water
NOT liquid
for 1 mark each
2
(Accept ratio of molecular KNO3 : PbC12 is 2:1 for 2 marks)
(do not accept relative number of atoms in each compound)
One is a solid, one is a solution – worth 1 mark
[4]
M17.
idea that
Page 96
•
contains nitrogen atoms
•
contains hydrogen atoms
•
atoms are chemically bonded
•
ratio of one nitrogen to three hydrogen (atoms) formula of ammonia is NH3
for 1 mark each
NOT linked/joined
[4]
M18.
(a)
Calcium
No of protons
Phosphorus
Fluorine
15
No of neutrons
10
No of electrons
20
for 1 mark each
3
(b)
(i)
gain of electron(s)
from (atoms) (of) calcium
for 1 mark
2
(ii)
Ca+
gains 1 mark
but superscript only Ca2+ / Ca ++
gains 2 marks
2
(c)
atoms
electrons
molecule(s)
not compound
Page 97
each for 1 mark
3
(d)
(i)
ideas that
•
ionic – strong forces between ions
•
molecular – weak forces between molecules
each for 1 mark
2
(ii)
ideas that
•
ionic – ions/charged particles are free to move
•
molecular -molecules do not carry a charge
each for 1 mark
2
[14]
•
correct use of react/reaction/reactants NOT mixed added to
join/combine/displace
NOT equals
M19.
•
correct use of produce/products/gives/forms/makes/creates
•
reactants correctly identified
•
products correctly identified
(copper oxide reacts with sulphuric acid to produce copper sulphate
and water, will be awarded all 4 marks)
for 1 mark each
Reactants must be correctly identified for ‘react’ mark to be given. Similarly for products
[4]
##
(a)
Fe2 [56 × 2] or 112
O3 [16 × 3] or 48
each gain 1 mark
Page 98
but Mr = 160
gains 3 marks
3
(b)
[Fe2 O3 + 2A1 → 2Fe + A12 O3]
160 → 112 (NB Credit if unworked
(or value
(or value but should be totalled)
from (a))
from (a))
gains 1 mark
but
32 g. of Fe2 O3 → 32/160 × 112
gains 2 marks
but = 22.4
gains 3 marks
3
[6]
##
(a)
idea that
some of the outer electrons of the atoms are free to move
can move anywhere across the (giant) structure
the flow of electricity is a stream of electrons
each for 1 mark
or electrons carry a (negative electrical) charge
3
(b)
metal element
[shiny] appearance
[high] melting point
forms an oxide that reacts with acids to make a salt
1 of these for 1 mark
non metal element
forms an oxide that reacts with alkalis
with chlorine forms a molecular chloride
1 of these for 1 mark
semi-conductor suggests in between
this, or any other for 1further mark
[NB Maximum of 2 for arguing metal/non-metal only]
Page 99
Under each head
1 wrong reason → maximum of 1 available
2 wrong reasons → no mark available]
3
[6]
M22.
(a)
(i)
(ii)
13
27
each for 1 mark
2
(b)
each proton has a/1 positive charge and each electron has a/1 negative
charge OR electrons and protons have (equal but) opposite charges
there are equal numbers of protons and electrons in the atom/
so charges cancel or balance (each other)
each for 1 mark
2
(c)
PARTICLE
NUMBER OF
PROTONS
NUMBER OF
NEUTRONS
Fluorine atom
Fluoride atom
NUMBER OF
ELECTRONS
10
9
10
each for 1 mark
3
[7]
M23.
(a)
(i)
2 H2 + O2 → 2 H2O (allow H2 + ½O2 → H2O)
both circled for 1 mark
1
Page 100
(ii)
4 A1 + 3 O2 → 2 A12O3
all circled for 1 mark
1
(b)
idea that:
must end up with the same number of atoms
otherwise matter is shown to be lost/gained
doesn’t show correct amount of each element/compared
each for 1 mark
2
(c)
idea that:
oxygen has 2 electrons short in outer shell ) in words or
chlorine has 1 electron short in outer shell ) indicated on diagram
(shared pair/covalent bond with) hydrogen
atom supplies one further electron*
*(but do not allow hydrogen gives away electron or ionic bond)
for 1 mark each
3
[7]
M24.
(a)
reference to
hydrogen (atoms)
)
nitrogen (atoms)
)
each for 1 mark
but not molecules
ratio of 1N to 3H atoms
for 1 further mark
or 1 nitrogen atom and 3 hydrogen atoms
(ignore any incorrect statements about nature of bonding)
3
(b)
evidence of
H=1
N = 14
O = 16
gains 1 mark
but
H=1
N = 14
O = 16 × 3 or 48
Page 101
gains 2 marks
but 63
gains 3 marks
3
[6]
M25.
(a)
(i)
lead chloride/product of lead + chloride ions is insoluble (in water)
for 1 mark
1
(ii)
Pb2+ + 2C1¯ → PbC12 *(s)
(allow (Pb)2+ 2 (C1–) )
formula
solid state symbol
balancing
for 1 mark each
3
(b)
copper hydroxide Cu(OH)2
each for 1 mark
lead sulphate
PbSO4
each for 1 mark
no precipitate
for 1 mark
Allow 1 mark for correct formula Na2SO4 in (i)
Allow 1 mark for correct formula Mg (NO3)2 in (ii)
0 marks for any formula in (iii)
5
[9]
M26.
(a)
correct representation of 1 atom of hydrogen e.g.
Page 102
gains 1 mark
but correct representation of 1 molecule of hydrogen e.g. or H-H
gains 2 marks
2
(b)
idea that:
hydrogen/metals form positive ions/lose electrons
gains 1 mark
but hydrogen and the metals form positive ions/lose electrons
gains 2 marks
hydrogen/non-metals form covalent bonds/share electrons
gains 1 mark
but hydrogen and the non-metals form covalent bonds/share electrons
gains 2 marks
4
[6]
M27.
(i)
carbon dioxide (allow CO2)
for 1 mark
1
(ii)
sodium nitrate (accept correct formula)
for 1 mark
1
[2]
Page 103
M28.
(a)
(i)
A calcium hydroxide/limewater/Ca(OH)2 not CaOH
(ii)
B calcium oxide/Quicklime/CaO
(iii)
C hydrogen/H2 (accept correct formulae)/ not H2/H
each for 1 mark
3
(b)
(i)
idea that
electrons are lost (by the calcium atom)
gains1 mark
but two electrons are lost (by the calcium atom)/lose outer electrons to get full
shell
gains 2 marks
calcium ions are 2+
for 1 mark
(ii)
electrons are gained (by the oxygen atom)
gains 1 mark
but two electrons are gained (by the oxygen atom)/gain electrons to get full
outer shell
gains 2 marks
oxygen ions are 2–
for 1 mark
6
(b)
(c)
(i)(ii) needs:
electron loss/gain
number (2)
charge (+/–)
idea that
they are held together by many/strong forces/bonds
a lot of energy/high temperature is required to break these forces/bonds
each for 1 mark
2
[11]
Page 104
##
(a)
Idea that
the electrons do not belong to specific atoms/delocalised electrons
[credit if done on appropriate diagram]
metal atoms form positive ions
the attraction which exists between particles with opposite charges, holds the metal
together
no specific bonds exist between adjacent atoms/ions
atoms/ions can slide over each other so allowing metals to bend
each for 1 mark
5
(b)
some electrons in the structure are delocalised/free to move
for 1 mark
these free electrons carry the electric current
for 1 mark
from left to right across the period, atoms of elements have
more free electrons
gains 1 mark
but from left to right across the period, atoms of elements have more free
electrons because they have more electrons in the outer shells
gains 2 marks
4
[9]
M30.
(a)
(i)
sodium ions and chloride ions
(allow sodium chloride/salt) [not “chlorine”] for 1 mark
1
(ii)
sodium ions and chloride ions
(allow sodium chloride/salt) for 1 mark
H + ions (allow hydrochloric acid)
for 1 mark
2
Page 105
(b)
H+ + OH– → H2O
[N.B Na+ and Cl– may also be present]
+
H ions from acid
OH– ions from alkali
each for 1 mark
[N.B First mark lost if changes on ions not shown]
3
[6]
##
(a)
both reactions slow down with time;
both reactions produce same volume of hydrogen
each for 1 mark
2
(b)
idea rate is faster with powder
or idea rate is slower with ribbon
(allow powder completed before ribbon) for 1 mark
1
[3]
-
##
(a)
hydrogen
for 1 mark
1
(b)
chloride ions are negative;
negative ions move to positive electrode
each for 1 mark
2
(c)
any one use of chlorine e.g.
sterilisation;
bleaching;
making plastics
any one for 1 mark
1
Page 106
[4]
##
(a)
sodium ions and chloride ions (not chlorine)
allow sodium chloride/salt/common salt
for 1 mark
1
(b)
H+ + OH– →H2O
H+ from (hydrochloric) acid
OH- from alkali/sodium hydroxide
lose 1 mark if no charge shown disregard other ions
each for 1 mark
3
[4]
-
M34.
(a)
same number/six electrons;
same number/six protons;
react in same way not same element or both carbon
any two for 1 mark each
2
(b)
different number of neutrons
gains 1 mark
but
C
or
has two more neutrons
gains 1 mark
different mass number
or
but two mass units bigger
gains 2 marks
C
has 8 neutrons while
C
Page 107
has 6 neutrons
gains 2 marks
2
[4]
##
(a)
covalent bonds
for 1 mark
1
(b)
any reference to shared electrons
gains 1 mark
but idea that bond is shared pair of electrons
gains 2 marks
2
[3]
##
(a)
positive
for 1 mark
1
(b)
any reference to loss of electrons
for 1 mark
reference to charge being +2 (in (a)) or to loss of 2 electrons (in (b))
for 1 mark
2
[3]
M37.
(a)
any one from
(as a) catalyst
or to mix with promoters
Page 108
to speed up the reaction (process)
or process is quicker do not credit just it is quicker
to save energy
to reduce costs
or process is cheaper
do not credit just it is cheaper
larger surface area
(than lumps of iron)
or larger surface area for the
(catalysed) reaction (to take place)
1
(b)
(i)
water or steam
and methane
or natural gas
or North Sea gas
both required either order
1
(ii)
EITHER
more (chance) of them colliding / coming into contact
do not credit just faster
OR volume of the product / ammonia less than / only half the
volume of the reactants / the nitrogen and hydrogen
1
(iii)
EITHER
680 (tonnes)
OR 28 (of nitrogen) → 34 (of ammonia)
accept any correct 14 : 17 ratio
1
560 (of nitrogen) → 34 × 20 (of ammonia)
3
[6]
M38.
(a)
This part was not marked
1
Page 109
(b)
electrolysis
1
because calcium is more reactive (than aluminium or carbon)
accept it is more reactive
or very reactive
1
OR
in a blast furnace
1
because calcium is less reactive (than carbon or lower)
1
(c)
any equation from
1 mark for correct formulae
1 mark for balancing
2ZnO + C → 2Zn + CO2
ZnO + CO → Zn + CO2
ZnO + C → Zn + CO
1
[5]
M39.
(a)
(i)
ammonia and hydrogen chloride
both required either order
accept formulae if correct in every detail
1
(ii)
ammonium chloride / NH4Cl
do not credit ammonia chloride
1
(iii)
the fumes / gases / are poisonous / toxic
or ammonia and hydrogen chloride are
poisonous / toxic / lethal
accept just ammonia is poisonous / toxic
accept just hydrogen chloride is
poisonous / toxic
accept vapour is poisonous / toxic
do not credit just fumes are dangerous
or harmful
Page 110
1
(iv)
nitrogen
do not credit N/N2
1
hydrogen
do not credit H/H2
1
molecule
do not credit compound or mole
1
covalent
accept single / molecular
1
(b)
(i)
proton
neutron
electron
either all three correct
or one or two correct
however do not credit a response
which is repeated
2
(ii)
protons and neutrons
both required in either order
1
[10]
M40.
(a)
(i)
corners
accept an arrow to any corner
1
(ii)
more (surface) exposed
accept can be attacked from more
directions or more space around it
1
Page 111
(b)
(i)
1
any two pairs from
more concentrated
answers may be in either order
do not accept more acid
do not accept more powerful or
stronger (but stronger is neutral)
a reference to sulphuric acid is neutral
1
more particles to hit the solid
accept more collisions per second
do not accept more collisions
1
2
hotter solution or increasing temperature
(faster) particles hit more often
or harder
accept particles have more energy
or are more powerful or
more successful collisions
1
3
stirring
more surface area exposed or
particles available
accept more collisions per second
do not accept more collisions
1
(ii)
cut it up or increase the surface area
accept grind it up or powder it
or flatten it do not accept make it smaller
or use a smaller piece
1
more particles are exposed or available or can react
accept heat it and there are more
successful collisions for both marks
1
[8]
Page 112
M41.
(i)
hydrogen, hydroxide and sulphate
all three and no others
any order
do not credit any formula(e)
1
(ii)
the anode is positive
1
(so) only the negative ions are attracted to it
or (so) only the hydroxide ions and the sulphate ions are
attracted (to it)
or (so) only the anions are attracted (to it)
1
(iii)
2H2O + O2 + 4e–
1
[4]
M42.
(a)
(i)
sodium........ positive or +
both required
1
chloride... negative or –
both required
do not credit chlorine
1
(ii)
ions not free (to move) in solid crystal / lattice
ions are free to move when sodium chloride is molten
1
or ions are mobile
do not credit when ions are molten
allow 'particles' for ions (1) mark
do not credit electrons etc
1
(iii)
dissolved in water
or in aqueous solution
accept in solution
Page 113
accept in water
or when a gas/ vapour or solid it will not
1
(b)
(i)
40
1
(ii)
(total) number of protons and neutrons (in the nucleus)
1
(c)
(i)
2Ca + O2 -+ 2CaO
accept any 2n : n : 2n ratio
do not credit if any other change has been made
1
(ii)
any two from
electron(s) is / are lost
from the outer shell / orbit / ring
or from the shell furthest the nucleus
or from the 4th shell
two / both (electrons are lost)
accept two electrons are lost for (2)marks
accept both electrons are lost from the
atom for (1) mark
2
[10]
M43.
(a)
(i)
rings of 2, 8 and 3 electrons
credit 2, 8, 3 pay particular attention to the outer shell in
diagrams
1
(ii)
rings of 2, 8 and 7 electrons
credit 2, 8, 7 pay particular attention to the outer shell in
diagrams
1
(b)
(i)
labels not required on atoms
charges need to be shown on ions
reference to outer shell is required otherwise a maximum of
two marks
Page 114
structure of atoms/ions marks
(ring of 2, 8, 1 for sodium) or the outer shell of sodium only contains 1 electron
credit 2, 8, 1 or an ion 2, 8 or two circles and 1 electron in
outer shell
1
(ring of 2, 6 for oxygen) or outer shell only contains 6 electrons
credit 2, 6 or an ion 2, 8 or two circles
1
transfer of electrons mark
two sodiums needed to supply two outer electrons to oxygen to complete
the (one oxygen's) outer shell
award maximum of two marks if a covalent structure is given
credit two rings of electrons for sodium showing outer
electrons transferring to outer shell of one oxygen for three
marks
do not accept diagrams showing overlapping rings for third
mark
1
(ii)
loses an electron
credit atoms lose electrons or oxygen takes the electron
ignore oil rig
1
[6]
M44.
(a)
(i)
8
ammonia
do not credit ammonium
sulphuric acid
do not credit just sulphuric; credit sulfuric acid
do not credit hydrogen sulphate
3
(ii)
(as a) fertiliser
1
Page 115
(iii)
nitric (acid)
accept HNO3 if correct in every detail
1
(b)
(i)
chemical change (in which)
or under suitable conditions
1
product(s) can be converted to reactant(s)
or direction of reaction can be reversed
or equilibrium can be achieved
do not credit reaction can be reversed
1
(ii)
air
or (the) atmosphere
1
(iii)
made of atoms
1
which are all the same
credit the idea that the particles (in an element) are all the
same even if the name of the particles (the first mark) is
incorrect
or which have the same number of protons
or which have the same atomic number / proton number
it cannot be broken down into anything simpler (2) marks
1
[10]
M45.
(a)
CaCO3 + 2HC1 → CaC12 + CO2 + H2O
one mark for CO2 and H2O or H2CO3
one mark for balancing the equation
2
(b)
(i)
linear suitable scale for y axis
± one small square
1
accurate plots
Page 116
deduct one mark for each error plot
1
smooth curve through the points or a line of best fit
this mark requires a neat smooth curve
1
(ii)
curve becomes almost horizontal at or above 268.5
do not credit a straight line reaching 268.5 at 11 mins
accept a plot at 268.6
1
(iii)
steeper initial part to curve
1
becoming nearly horizontal between 268.6 and 268.4 g
1
[8]
M46.
NOTE
In this question and throughout the Paper, if the name of a chemical is
asked for, then the formula is acceptable only if it is correct in every detail.
If the name is correct and the candidate has tried to be ‘helpful’ by giving,
in addition, an incorrect version of the formula, then this is acceptable
provided it does not lead to ambiguity.
(i)
nitric (acid)
accept HN03
1
(ii)
sulphuric (acid)
accept H2SO4
1
(iii)
heat given out
or temperature rise
or energy given out
Page 117
or steam
do not credit just ‘use a thermometer’
do not credit just 'change in temperature'
1
(iv)
neutralisation
accept neutralise
accept neutral
accept formation of salt or water
do not credit exothermic
1
[4]
M47.
(i)
two
or 2
1
(ii)
magnesium and chloride
either order
not positive / negative
do not credit’chlorine’
accept Mg++ and Cldo not credit just Mg and Cl–
accept cation(s) and anion(s)
1
(iii)
2
1
(iv)
electrons
accept charges
1
(v)
any three from
•
(is a) giant structure/lattice structure
•
crystalline / hard
accept just 'crystals(s)’
•
high melting point / solid
Page 118
•
high boiling point
•
conductor (of electricity) when dissolved in water
or conductor (of electricity) when ions are free to move
•
conductor (of electricity) when molten
•
soluble in water
3
[7]
M48.
(a)
both correct in each row
electron ...– (1)
allow negative
1
1 .......... 0
allow neutral or none
1
proton .....+ (1)
allow positive
1
(b)
(i)
protons...electrons
both correct in correct order
1
(ii)
protons....neutrons
both correct in either order
1
(c)
(i)
sodium fluoride
do not credit sodium fluorine
1
NaF
must be correct in every detail
do not credit NAF and the like
1
Page 119
(ii)
ionic
accept ion (bonding)
do not credit ironic or iron (bonding)
1
(iii)
electron transferred from sodium to fluorine
accept electron transferred from metal to non-metal
either positive sodium ion and negative fluoride ion
or correctly identified by the symbols Na+ and F- accept
‘positive sodium ion and negative fluorine ion’
1
or attracted because have opposite charge(s)
or (atoms/ions) form an (ionic) lattice or (atoms/ions) form a
crystal
e.g.
or both marks may be gained by a suitable dot and cross diagram
1
[10]
M49.
(a)
Bunsen (burner)
accept spirit burner do not credit candle
1
(b)
blue
1
white
credit (1) if both colours correct but answers are reversed
1
to cool the tube (B)
accept answers which anticipate part (d) e.g. ‘to condense
the water vapour’ or gases or vapours
1
Page 120
(d)
(i)
water
do not credit ‘condensation’
1
(ii)
(Water) vapour from the crystals (from tube A)
accept steam or steam from tube A
1
condenses or cools
accept turns to (liquid) water
1
(e)
add water
gets hot or hotter or warm or warmer turns into solution
dissolves
or the temperature rises or there is an exothermic reaction
accept steams or hisses ignore any reference to colour(s)
2
(f)
sulphuric acid
accept H2S04 only if correct in every
detail
1
[10]
M50.
graph steeper
1
becomes horizontal
1
reaches twice the height_, 40 cm3
1 cm3
Page 121
1
[3]
M51.
(a)
Mg + 2H+ → Mg2+ + H2
* reactants correct in every detail
* products correct in every detail
if the spectator ions are sown then (1) mark should be
credited but only if they are shown correctly on both sides
e.g.
Mg + 2H+ + 2CI- → Mg2+ + 2CI- + H2
2
(b)
24 (parts) of magnesium → 2 (parts)
1
of hydrogen or equally clear working (so) 6 grams/g (are needed)
1
unit required
(c)
(i)
two (and no more) atoms shown to be sharing their single electrons
examples
do not credit if anything which contradicts the impression that
these are hydrogen atoms
1
(ii)
(single) covalent (bond)
1
(d)
(×100) = 6 (just 6 is worth (1) mark)
1
× 100 = 6 or similar is (0)
do not credit 5.8823529 and the like
Page 122
1
[8]
M52.
(a)
proton + (1)
both required
neutron 1
both required
electron – (1)
both required
3
(b)
2.8.3
accept words or diagram to this effect
1
(c)
(i)
24
1
(ii)
52
1
(d)
any one of
•
gains one or more electrons
accept gains an electron
•
becomes an anion
do not credit becomes an ion
•
becomes a negative ion
1
(e)
sodium ions have a (single) positive
charge and chloride ions have a
(single) negative charge
do not credit ‘chlorine ions’ but
allow this error to be carried forward
1
Page 123
ions with opposite charge are
attracted (to each other)
or the positive ions and the negative ions are attracted (to
each other)
or the sodium ions and the chloride ions are attracted (to
each other)
1
(positive and negative) ions are
arranged alternatively (in each
direction or dimension)
or ions with the same charge are repelled (by each other) no
mark for just ionic bonds
1
[10]
Cl2 + 2Br → 2Cl + Br2
formulae correct for elements
M53.
1
correct charge on both ions
1
credit balanced if Cl2 and Br2 included
1
[3]
M54.
(a)
Cu
1
Fe
1
Zn
1
(b)
one significant use for each metal
do not credit vague answers such as ‘in experiments’ and
Page 124
the like
do not credit the same use more than once
copper
examples:
do not credit diet supplement
1
•
coins or coinage (metal) or make alloys or bronze or brass
•
conducting electricity or (electrical) wiring or motors or cables
•
(domestic) (water) pipes
•
heat exchangers
•
roofing
•
steam pipes
•
stills or cooking utensils
accept any specified still e.g. whisky still
•
bracelets or rings
iron or steel answers
examples:
do not credit diet supplement
* access-hole covers (sometimes known as ‘manhole’ covers)
* catalyst (in the production of ammonia)
* manufacture of steel(s) or in the basic oxygen process
* named vehicle or transport or machinery or railings
any other uses for iron and steel can be credited provided
that the use is clear so, for example, ‘bridges’ and ‘railway
lines’ would be creditworthy but do not credit ‘buildings’ and
‘transport’ which are too vague
1
zinc
examples:
do not credit diet supplement
* brass manufacture
* die castings
* rust prevention
* to galvanise (iron or steel) or (as a) protective coating
* battery casing
Page 125
1
(c)
any four general properties of
do not credit hard or strong or tough or magnetic
•
are not brittle
accept can be bent (into shape) or flexible
•
can be hammered (into shape)
accept are malleable
•
can be stretched (into shape)
accept are ductile
•
(good) conductors of heat
accept just ‘(good) conductor’ once only
•
(good) conductors of electricity
•
high boiling points
•
high density or heavy or dense
•
high melting points
•
ringing sound when struck
accept sonorous
•
solids (at room temperature)
accept shiny (when polished) or silvery
4
(d)
any one of
do not credit electron references
* (good) conductor (of electricity) when molten or liquid
accept dissolves in water or crystalline
* (good) conductor (of electricity) when in aqueous solution
accept (good) conductor (of electricity) when dissolved in
water
* high melting point or high boiling point
do not credit just ‘solid’
1
Page 126
(e)
(i)
electron from A to B
both parts required
1
(ii)
different numbers of protons
accept different atomic numbers do not credit references to
neutrons
1
[13]
M55.
(a)
Zn + 2HC 1 → ZnC12 + H2
1
(b)
(i)
12.5
1
(ii)
steeper curve same volume of gas evolved
do not credit two intersects of straight lines
accept a sharp bend
2
(iii)
any two from:
stir it
accept mix it better
heat it
accept warm it
use a more finely divided catalyst
accept use a better catalyst or more finely divided zinc
do not credit use acid of a higher
2
(c)
(i)
any one from
zinc is more reactive than copper
accept zinc is above copper in the reactivity series
zinc displaces copper
accept it is higher than copper in the reactivity series
1
Page 127
(ii)
zinc + copper sulphate → copper + zinc sulphate
ignore the presence of acid or water
accept a balanced equation
1
[8]
M56.
(i)
(Y)
more gas / carbon dioxide given off
1
(ii)
(X)
curve / slope steeper
accept rises more rapidly / only took 30 seconds
1
(iii)
(flat)
since calcium carbonate /
substrate all used up
accept the reaction has stopped /
no more gas is being produced
1
1
[3]
M57.
73 (seventy three)
if answer is incorrect allow 1 mark for the correct proportion
that H2:HCl is 1:2
and 1 mark for 36.5
[3]
Page 128
M58.
(i)
(ii)
1
weak forces
accept weak bonds
1
between molecules / intermolecular
reject intramolecular
1
[3]
M59.
(a)
ammonium nitrate
accept NH4NO3
do not accept ammonia nitrate
1
(b)
different reactions need different catalysts
1
(c)
they are used over and over again
accept they are reused
accept they are not used up
accept they are not changed
recycling is neutral
1
(d)
any two from
Page 129
they speed up reactions
they reduce energy requirements
accept allow reactions to take place at a lower temperature
they reduce costs
accept make process more economic
2
(e)
(high pressure) increases the
frequency of collisions
accept more collisions
move faster is neutral
1
this increases the rate of reaction
accept ‘more successful collisions’ for 2 marks
1
[7]
M60.
(i)
4 and 1
both answers must be correct
1
(ii)
53.5
if incorrect relative formula mass
allow 1 mark for correct working
accept e.c.f. from c(i) for 2 marks
2
[3]
M61.
(a)
LHS lithium + water
accept Li and H2O
accept hydrogen oxide for water
1
RHS hydrogen + lithium hydroxide
accept H2 and LiOH
Page 130
ignore attempts at balancing
ignore charges
1
(b)
Quality of written communication
One mark for the correct use of any
three of the terms atom, covalent,
bond(ing), saturated, hydrocarbon
or alkane
1
any three from:
one / the carbon (atom)
reject molecules once
four hydrogen (atoms)
shape / properties neutral
CH4
hydrocarbon
saturated / single bond
covalent bond / shared electrons
alkane
reject ionic bond
3
[6]
M62.
(a)
(i)
2.25
correct answer gains three marks
if incorrect allow 1 mark for 2 correct
readings (130 and 175) and further mark for 45 ÷ 20
allow e.c.f.
3
(ii)
concentration of reactant(s) lower
1
fewer collisions per second / time unit
1
Page 131
(b)
labour costs lower / enzymes costs lower
not stop and start
1
[6]
M63.
(a)
(i)
catalyst / enzyme
1
(ii)
any two from
do not accept increase volume of peroxide
•
heat
•
stir / shake
•
increase concentration of peroxide / catalyst
2
(b)
oxygen lost
do not allow incorrect gas
1
[4]
M64.
(a)
10.86
accept answers between 10.64 to 10.9
if answer is incorrect allow 1 mark for
rfm FeSO4 = 152
2 marks for 152 × 4/56
3
(b)
2 Fe + 3 H2SO4 → Fe2(SO4)3 + 3H2
accept other correct multiples for balancing
1
[4]
Page 132
M65.
(a)
Quality of written communication: All scientific words used correctly
(covalent, bonds, atoms)
1
any two from
•
large numbers of covalent bonds
allow giant lattice / structure
•
between atoms
do not accept between molecules
•
(covalent) bonds strong
accept need much energy to break
2
(b)
each carbon has 4 electrons
1
one shared pair
1
four shared pairs
1
[6]
Page 133
M66.
(a)
nitrogen
accept N or N2
1
(b)
the reaction is exothermic
accept the reaction releases heat energy
1
(c)
water
accept H2O or hydrogen oxide
1
(d)
with ammonia and nitric acid
1
neutralisation
accept a correct description of reacting (ammonia and nitric
acid)
1
[5]
M67.
(a)
A faster because: the graph line steeper / the reaction had stopped earlier
accept sample B slower because: the graph line was less
steep / the reaction stopped later
A because CO2 given off faster / fizzes more for 1 mark
B because CO2 given off slower / fizzes less for 1 mark
2
(b)
increases the speed / energy of the (hydrochloric acid) particles
1
collide more frequently
1
collide more energetically / successfully
accept more successful collisions = 2 marks
1
[5]
Page 134
M68.
36.8 / 37
correct answer, no workings = 3 if incorrect, allow 1 mark for
rfm FeSO4 = 152
or if incorrect rfm, allow 1 mark for 56/Y × 100 where Y is
incorrect formula mass
allow 2 marks for
× 100
[3]
M69.
(a)
endothermic (reaction)
accept thermal decomposition
1
(b)
gives out heat (energy)
accept exothermic (reaction)
1
turns blue
accept goes to hydrated copper sulphate
1
[3]
M70.
(a)
oxidising
1
(b)
(i)
oxygen
ignore any numbers
1
Page 135
(ii)
(catalyst) speeds up a (chemical reaction)
accept changes the rate (of reaction)
1
[3]
M71.
(a)
(i)
2 Mg + O2 → 2 MgO
both 2s needed
allow O2 or any correct multiple
1
(ii)
solid
1
gas
1
(b)
MgCl2 / C12Mg
do not accept MG mg mG CL cl cL
ignore charges
1
[4]
M72.
(a)
1400
1
(b)
980
correct answer gains full credit
160 tonnes Fe2O3 produces 112 tonnes Fe
if incorrect allow one mark for relative formula mass iron
oxide = 160
allow e.c.f.
1400 tonnes Fe2O3 will produce 1400 / 160 × 112 tonnes Fe
use of 2000 tonnes Fe2O3 – deduct one mark only if
working out is correct
4
Page 136
[5]
M73.
(a)
X – (metal) atom / ion
1
Y – electron
1
(b)
free electrons or electrons move
1
(allow metal) atoms / ions to slide over each other
OR
bonding non - directional for 2 marks
1
[4]
M74.
(a)
the concentration of the (nitric) acid is decreasing
accept the number of acid particles is
decreasing or there are fewer collisions
1
(the volume of carbon dioxide remains at 83 cm3)
when the concentration of the (nitric) acid is zero
accept no acid remains or all the acid
is used up or no acid particles
1
(b)
line starts at origin is steeper and remains to the left of the original line
1
graph line levels off at 83 cm3 and before 12 minutes
tolerance
square
1
Page 137
(c)
change the temperature
accept increase or decrease the temperature
accept change (increase or decrease) the concentration (of
the nitric acid)
ignore amounts of reactants or changes in pressure or
stirring or use of catalyst
1
[5]
M75.
(a)
the concentration of the (nitric) acid is decreasing
accept the number of acid particles is
decreasing or there are fewer collisions
1
(the volume of carbon dioxide remains at 83 cm3)
when the concentration of the (nitric) acid is zero
accept no acid remains or all the acid
is used up or no acid particles
1
(b)
line starts at origin is steeper and remains to the left of the original line
1
graph line levels off at 83 cm3 and before 12 minutes
tolerance
square
1
(c)
change the temperature
accept increase or decrease the temperature
accept change (increase or decrease) the concentration (of
the nitric acid)
ignore amounts of reactants or changes in pressure or
stirring or use of catalyst
1
[5]
Page 138