C2.1Structure and bonding, C2.2 Structure and properties & C2.3 Atomic Structure Foundation
Q1.
(a)
(i)
electron
The diagram represents an atom of nitrogen.
Use words from the box to label the diagram.
neutron
nucleus
proton
(2)
(ii)
Draw a ring around the mass number of this atom.
5
7
14
21
(1)
Q2.
(a)
An atom of aluminium can be represented as shown below.
In this atom of aluminium the number of protons is ............................. and
the number of neutrons is ...............................
(2)
(b)
Which statement in the table below describes the mass of an electron?
Tick ( ) one box.
Statement
Tick ( )
Electrons have a very small mass compared to protons.
Electrons have about the same mass as protons.
Electrons are much heavier than protons.
Electrons have about the same mass as neutrons.
(1)Page
1
Q3.
The diagram represents an atom of beryllium.
Use a number from the box to complete each sentence.
4
(a)
7
9
12
The atomic number (proton number) of this atom is
.
(1)
(b)
The mass number of this atom is
.
(1)
(Total 2 marks)
Q4.
Sodium reacts with chlorine. The reaction forms sodium chloride.
(a)
Use words from the box to answer the questions.
compound
element
hydrocarbon
mixture
Which word best describes:
(i)
sodium .......................................................................
(1)
(ii)
sodium chloride? ........................................................
(1)
(b)
When sodium reacts with chlorine the sodium atoms change into sodium ions.
The diagrams below represent a sodium atom and a sodium ion.
Page 2
Use the diagrams to help you explain how a sodium atom turns into a sodium ion.
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c)
(i)
The diagram below represents a chlorine atom.
When chlorine reacts with sodium the chlorine forms negative chloride ions.
Complete the diagram below to show the outer electrons in a chloride ion (Cl–).
(1)
(ii)
Chloride ions are strongly attracted to sodium ions in sodium chloride.
Explain why.
...............................................................................................................
...............................................................................................................
(1)
Q5.
The drawing shows a container of a compound called magnesium chloride.
Page 3
(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?
................................................. 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)
Q6.
This question is about giant structures. Diamond, graphite and silicon dioxide all have giant
structures.
(a)
The diagrams show the structures of these three substances. Draw a line from each
structure to its name.
Page 4
(2)
(b)
Complete the sentences using words from the box.
covalent
four
hard
ionic
shiny
soft
three
two
(i)
Diamond, graphite and silicon dioxide have high melting points because all the
atoms in their structures are joined by strong ............................................... bonds.
(1)
(ii)
In diamond each atom is joined to ............................................... other atoms.
(1)
(iii)
Diamond can be used to make cutting tools because it has a rigid structure which
makes it very ................................................
(1)
(iv)
In graphite each atom is joined to ............................................... other atoms.
(1)
(v)
Graphite can be used to make pencils because it has a structure which makes it
................................................
(1)
(c)
When a diamond is heated to a high temperature and then placed in pure oxygen it burns.
Carbon dioxide is the only product. Name the element in diamond.
...................................................................................
(1)
Q7.
The diagram represents a particle of methane.
Page 5
(a)
What is the formula of methane? ...............................................................................
(1)
(b)
Choose a word from the box to answer the question.
atom
ion
molecule
Which of the words best describes the methane particle shown in the diagram?
.................................................
(1)
(c)
Choose a word from the box to answer the question.
covalent
ionic
metallic
What is the type of bonding shown in the diagram?
..................................................
(1)
(Total 3 marks)
Q8.
This barbecue burns propane gas.
The diagram represents a propane molecule.
(a)
What is the formula of propane? ........................................................................................
(1)
(b)
(i)
the particle represented by the symbols ○
Draw a ring around the name of
Page 6
and × in the diagram.
electron
neutron
proton
(1)
(ii)
Draw a ring around the type of bonding that holds the atoms together in a propane
molecule.
covalent
ionic
metallic
(1)
(c)
Under high pressure in the cylinder propane is a liquid.
Liquid propane evaporates easily to form a gas when the tap on the cylinder is opened.
Draw a ring around the correct answer in each box to explain why propane evaporates
easily.
Propane has a
high
low
boiling point because it consists of
large
small
molecules.
(1)
Q9.
This picture shows a sword. The sword is about 3400 years old. It is made of an alloy called
bronze.
Bronze is made from copper and tin. Bronze made better swords than pure copper. This is
because bronze is harder than pure copper.
(a)
Draw a ring around the correct answer to complete the sentence.
metals.
An alloy is a mixture of
molecules.
non-metals.
(1)
(b)
Pure copper can be quite easily bent out of shape.
Which two statements in the table explain why copper can be bent?
Tick ( ) two boxes.
Statements
Tick ( )
Copper atoms are arranged in layers.
Page 7
Copper atoms are joined by strong covalent bonds.
Copper atoms can slide over each other.
Copper is made of small molecules.
(2)
(c)
Which one statement in the table explains why bronze is harder than pure copper?
Tick ( ) one box.
Statements
Tick ( )
Copper and tin atoms are the same size.
The layers of atoms are distorted in bronze.
The copper and tin atoms are joined by strong
covalent bonds in bronze.
(1)
Q10.
Iron is the main structural metal used in the world.
(a)
The diagram represents the particles in iron, Fe.
Draw a ring around the correct word in the box to complete the sentence.
atoms
Iron is described as an element because all the
compounds
are the same.
metals
(1)
(b)
Stainless steel is mostly iron.
The diagram represents the particles in stainless steel.
Use the correct words from the box to Page 8complete the sentences about alloys.
metal
mixture
molecule
polymer
smart
structure
Stainless steel is an alloy because it is a ...........................................................................
of iron, chromium and nickel.
An alloy is made up of more than one type of ................................................................ .
Stainless steel alloys are harder than iron because the different sized atoms added change
the ............................................................................... .
An alloy that can return to its original shape after being deformed is called a
..................................................................... alloy.
Page 9
(4)
Q11.
(a)
Read the article about the use of nanoparticles in sun creams.
Sun creams
Many sun creams use nanoparticles. These sun creams are very good at absorbing
radiation, especially ultraviolet radiation. Owing to the particle size, the sun creams
spread more easily, cover better and save money because you use less. The new
sun creams are also transparent, unlike traditional sun creams which are white. The
use of nanoparticles is so successful that they are now used in more than 300 sun
cream products.
Some sun creams contain nanoparticles of titanium oxide. Normal-sized particles of
titanium oxide are safe to put on the skin.
It is thought that nanoparticles can pass through the skin and travel around the body
more easily than normal-sized particles. It is also thought that nanoparticles might
be toxic to some types of cell, such as skin, bone, brain and liver cells.
(i)
How is the size of nanoparticles different from normal-sized particles of titanium
oxide?
..........................................................................................................................
(1)
(ii)
Suggest how the size of nanoparticles might help them to enter the body more easily.
..........................................................................................................................
..........................................................................................................................
(1)
(b)
Give two advantages of using nanoparticles in sun creams.
1 .................................................................................................................................
....................................................................................................................................
2 .................................................................................................................................
....................................................................................................................................
(2)
(c)
Why might nanoparticles be dangerous inside the body?
...................................................................................................................................
...................................................................................................................................
(1)
(Total 5 marks)
Page 10
Q12.
(a)
The diagram represents an atom of nitrogen.
Label the diagram.
(3)
(b)
Ammonia has the formula NH3. It is made from nitrogen and hydrogen.
How many atoms are in an ammonia molecule? ..........................................
(1)
(c)
The diagrams show the electron arrangement in nitrogen and hydrogen.
Nitrogen
Hydrogen
Which diagram below, A, B, C or D, represents an ammonia molecule?
A
B
C
D
Write your answer in the box.
Diagram
(1)
(Total 5 marks)
Page 11
Q13.
(a)
Every chemical element has a chemical symbol. Choose the correct chemical
symbols from the box and complete the three spaces in the table.
C
Co
Cu
Fe
I
Ir
Zn
Name of element
Chemical symbol
Copper
....................................
Iron
....................................
Zinc
....................................
Zr
(3)
(b)
Give one use for each of the following metals. You should give a different use for each
metal.
Copper ......................................................................................................................
....................................................................................................................................
Iron ...........................................................................................................................
....................................................................................................................................
(2)
(c)
Give three physical properties which metals usually have.
1. ................................................................................................................................
....................................................................................................................................
2. ................................................................................................................................
....................................................................................................................................
3. ................................................................................................................................
....................................................................................................................................
(3)
(d)
Metals usually form ionic compounds. Give one property of an ionic compound.
....................................................................................................................................
....................................................................................................................................
(1)
Page 12
(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)
Q14.
This question is about fluorine and some of its compounds.
(a)
The diagram represents a molecule of hydrogen fluoride.
Draw a ring around the type of bonding that holds the hydrogen and fluorine atoms
together in this molecule.
covalent
ionic
metallic
(1)
Page 13
(b)
Fluorine is made in industry by the electrolysis of a mixture of potassium fluoride and
hydrogen fluoride.
(i)
Use one word from the box to complete the sentence.
gas
liquid
solid
To allow electrolysis to take place the mixture of potassium fluoride and
hydrogen fluoride must be .................................................. .
(1)
(ii)
The mixture of potassium fluoride and hydrogen fluoride contains fluoride ions
(F–), hydrogen ions (H+) and potassium ions (K+). Use one word from the box to
complete the sentence.
fluorine
hydrogen
potassium
During electrolysis the element formed at the positive electrode is
............................................................ .
(1)
Q15.
Read the article and then answer the questions that follow.
Hydrogen fuel for cars?
Hydrogen is an excellent fuel. On combustion it reacts with oxygen from the air to release a large amount of
energy. The only product of combustion is water which does not cause pollution. Hydrogen gas can be stored
under pressure in a cylinder but a leak of the gas could cause an explosion. It has been found that lithium
nitride can absorb and then release large volumes of hydrogen. Hydrogen stored in lithium nitride will not
explode. The problem is that the rate at which hydrogen is absorbed and then released from normal sized
particles of lithium nitride is slow. Recently scientists have made ‘nanosized’ particles of lithium nitride. The
‘nanosized’ particles have the advantage that they absorb and release the hydrogen much faster when
needed in the fuel cell.
(a)
Use information from the article to help you to answer these questions.
(i)
Give two reasons why hydrogen is an excellent fuel.
1 .........................................................................................................................
2 .........................................................................................................................
(2)
Page 14
(ii)
Hydrogen stored in lithium nitride is safer in an accident than a cylinder full of
hydrogen gas. State why.
...........................................................................................................................
(1)
(iii)
What is the advantage of using ‘nanosized’ particles of lithium nitride instead of
normal sized particles for storing hydrogen?
...........................................................................................................................
(1)
(b)
Lithium nitride is an ionic compound that contains lithium ions (Li+) and nitride ions
(N3–).
(i)
The periodic table on the Data Sheet may help you to answer this question. Which
diagram, A, B or C, represents the electronic structure of a lithium atom?
Write your answer in the box.
Diagram
(1)
(ii)
Tick ( ) the statement which describes how a lithium atom (Li) changes into a lithium
ion (Li+).
Statement
Tick ( )
A lithium atom loses a neutron.
A lithium atom loses an electron.
A lithium atom loses a proton.
(1)
(iii)
The diagram shows the electronic structure of a nitrogen atom.
Which diagram, A, B or C, represents
the electronic structure of a nitride ion (N3–
Page 15
)?
Write your answer in the box.
Diagram
(1)
(c)
The equation for the reaction of lithium nitride with hydrogen is:
Li3N + 2H2
What does the symbol
reversible reaction
LiNH2 + 2LiH
mean? Draw a ring around your answer.
endothermic reaction
neutralisation
(1)
(d)
Draw a ring around the correct answer in each box to complete the sentences.
much larger
(i)
‘Nanosized’ particles of lithium nitride will be
a little larger
much smaller
than normal sized particles of lithium nitride.
(1)
(ii)
One of the reasons why ‘nanosized’ particles have different properties
density
from normal sized particles is that they have a greater
mass
surface area
than normal sized particles of lithium nitride.
(1)
(Total 10 marks)
Page 16
Q16.
This question is about oxygen atoms.
(a)
(i)
Oxygen atoms have 8 electrons.
Complete the diagram to represent the arrangement of electrons in an oxygen atom.
Use crosses (×) to represent the electrons.
(1)
(ii)
Name the part of the oxygen atom that is labelled A on the diagram.
...............................................................................................................
(1)
(b)
Two isotopes of oxygen are oxygen-16 and oxygen-18.
oxygen-16
oxygen-18
Describe, in terms of particles, how an oxygen-18 atom is different from an oxygen-16
atom.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 4 marks)
Q17.
Use the Data Sheet to help you answer this question.
When sodium reacts with water it forms sodium ions.
The diagrams below represent the electron arrangements of some atoms and ions.
Which of the diagrams, A to E, represents the electron arrangement of each of the following?
(i)
A sodium atom, Na .............................
(ii)
A sodium ion, Na+ ..............................
(Total 2 marks)
Page 17
Q18.
Calcium and magnesium are elements. They are found in the Earth’s crust as compounds,
often carbonates and sulphates. Magnesium is also found as its chloride.
(a)
Calcium and magnesium are in the same Group in the Periodic Table.
State which Group this is.
.....................................................................................................................................
(1)
(b)
Use the Data Sheet to help you to answer this question.
(i)
Write the chemical formula of magnesium chloride.
...........................................................................................................................
(1)
(ii)
Name the type of bonding in magnesium chloride.
...........................................................................................................................
(1)
(Total 3 marks)
Q19.
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
........................................
.......................................
........................................
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)
Page 18
(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.
Explain why the ions in this lattice stay in place.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 10 marks)
Page 19
Q20.
Hydrogen chloride (HCl) can be made by the reaction of hydrogen (H2) with chlorine (Cl2).
(a)
The diagrams represent molecules of hydrogen and chlorine.
Draw a similar diagram to represent a molecule of hydrogen chloride (HCl).
You need show only the outer energy level (shell) electrons.
(1)
(b)
The word equation for the reaction of hydrogen with chlorine is shown below.
hydrogen + chlorine →
hydrogen chloride
Write a balanced symbol equation for this reaction.
.....................................................................................................................................
(2)
(c)
Hydrogen chloride gas reacts with magnesium to form the ionic compound called
magnesium chloride. Use the table of ions on the Data Sheet to help you to write the
formula of magnesium chloride.
.....................................................................................................................................
(1)
(d)
Why does magnesium chloride have a much higher melting point than hydrogen chloride?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
C2.3 Analysis and Quantitative Chemistry -
Page 20
Foundation
Q1.
Calcium oxide (quicklime) is made by heating calcium carbonate (limestone).
calcium carbonate → calcium oxide +
100 g
?
(a)
carbon dioxide
44 g
44 grams of carbon dioxide is produced when 100 grams of calcium carbonate is heated.
Calculate the mass of calcium oxide produced when 100 grams of calcium carbonate
is heated.
....................................................................................................................................
mass ......................... g
(1)
(b)
What mass of carbon dioxide could be made from 100 tonnes of calcium carbonate?
mass ....................... tonnes
(1)
(Total 2 marks)
Q2.
Follow the steps to find the percentage of iron in iron oxide.
Relative atomic masses: O 16; Fe 56.
(i)
Step 1
Calculate the relative formula mass of iron oxide, Fe2O3.
.....................................................................................................................................
.....................................................................................................................................
(1)
(ii)
Step 2
Calculate the total relative mass of just the iron atoms in the formula, Fe2O3.
.....................................................................................................................................
(1)
(iii)
Step 3
Calculate the percentage (%) of iron in the iron oxide, Fe2O3.
.....................................................................................................................................
.....................................................................................................................................
Percentage of iron ................................. %
(1)
(Total 3 marks)
Page 21
Q3.
(a)
A chemist was asked to identify a nitrogen compound. The chemist carried out an
experiment to find the relative formula mass (Mr) of the compound.
The Mr of the compound was 44.
Relative atomic masses: N = 14, O = 16
Draw a ring around the formula of the compound.
NO
NO2
N2O4
N2O
(1)
(b)
Potassium nitrate is another nitrogen compound. It is used in fertilisers. It has the formula
KNO3.
The Mr of potassium nitrate is 101.
Calculate the percentage of nitrogen by mass in potassium nitrate.
Relative atomic mass: N = 14.
.....................................................................................................................................
.....................................................................................................................................
Percentage of nitrogen = .............................. %
(2)
(Total 3 marks)
Q4.
Iron is an essential part of the human diet. Iron(II) sulfate is sometimes added to white bread
flour to provide some of the iron in a person’s diet.
(a)
The formula of iron(II) sulfate is FeSO4
Calculate the relative formula mass (Mr) of FeSO4
Relative atomic masses: O = 16; S = 32; Fe = 56.
.....................................................................................................................................
.....................................................................................................................................
The relative formula mass (Mr) = ..............................
(2)
Page 22
(b)
What is the mass of one mole of iron(II) sulfate? Remember to give the unit.
..............................
(1)
(c)
What mass of iron(II) sulfate would be needed to provide 28 grams of iron?
Remember to give the unit.
..............................
(1)
(Total 4 marks)
Q5.
Toothpastes often contain fluoride ions to help protect teeth from attack by bacteria.
Some toothpastes contain tin(II) fluoride.
This compound has the formula SnF2 .
(a)
Calculate the relative formula mass (Mr) of SnF2.
Relative atomic masses: F = 19; Sn = 119
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Relative formula mass (Mr) = ..........................................
(2)
(b)
Calculate the percentage by mass of fluorine in SnF2.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Percentage by mass of fluorine = .......................................... %
(2)
Page 23
(c)
A tube of toothpaste contains 1.2 g of SnF2. Calculate the mass of fluorine in this tube of
toothpaste.
....................................................................................................................................
....................................................................................................................................
Mass of fluorine = .......................................... g
(1)
(d)
The diagram represents the electron arrangement of a fluorine atom.
Explain how a fluorine atom can change into a fluoride ion, F–.
....................................................................................................................................
....................................................................................................................................
(2)
Q6.
The result of a process used to detect and identify the colours in two foods, A and B, is
shown.
(i)
Describe the differences between the colours used in food A and food B.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(ii)
Tick ( ) the name of the process used to detect and identify colours in food.
Process
( )
chromatography
extraction
hardening
(1)
Page 24
Q7.
Chromatography was carried out on a sample of soft drinks to check that they contained only
colours that were safe. This is the result.
Safe colours
Colours from the soft drinks
What conclusions about the safety of the colours in the soft drinks A, B, C and D can be made from the
results shown by chromatography?
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 2 marks)
Q8.
(a)
Suggest why it is important to be able to identify the colour additives in food.
....................................................................................................................................
....................................................................................................................................
(1)
Page 25
(b)
A brown colour used in sweets was analysed using chromatography. The results were
compared with those from E104 and E133.
What do the results tell you about the brown colour and its suitability for use in sweets?
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(c)
Once all the unsuitable colours are removed, the company claims that its sweets are now
‘free from artificial colours’.
Does this mean that the sweets contain no additives? Explain your answer.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 6 marks)
Page 26
Q9.
The diagram shows the main parts of an instrumental method called gas chromatography
linked to mass spectroscopy (GC-MS).
This method separates a mixture of compounds and then helps to identify each of the compounds
in the mixture.
(a)
In which part of the apparatus:
(i)
is the mixture separated? ...................................................................
(1)
(ii)
is the relative molecular mass of each of the compounds in the mixture measured?
...............................................................................................................
(1)
(b)
(i)
Athletes sometimes take drugs because the drugs improve their performance. One
of these drugs is ephedrine.
Ephedrine has the formula:
C10H15NO
What relative molecular mass (Mr) would be recorded by GC-MS if ephedrine was
present in a blood sample taken from an athlete?
Show clearly how you work out your answer.
Relative atomic masses: H = 1; C = 12; N = 14; O = 16.
...............................................................................................................
...............................................................................................................
...............................................................................................................
Relative molecular mass = .....................................
(2)
Page 27
(ii)
Another drug is amphetamine which has the formula:
C9H13N
The relative molecular mass (Mr) of amphetamine is 135.
Calculate the percentage by mass of nitrogen in amphetamine.
Relative atomic mass: N = 14
...............................................................................................................
...............................................................................................................
Percentage of nitrogen = ..................................... %
(2)
(c)
Athletes are regularly tested for drugs at international athletics events.
An instrumental method such as GC-MS is better than methods such as titration.
Suggest two reasons why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(d)
When a blood sample is taken from an athlete the sample is often split into two portions.
Each portion is tested at a different laboratory.
Suggest why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 10 marks)
Page 28
C2.1Structure and bonding, C2.2 Structure and properties & C2.3 Atomic Structure
Markscheme - Foundation
M1.
(a)
(i)
all three correct 2 marks
one correct 1 mark
2
(ii)
14
1
(b)
A
1
[4]
M2.
(a)
13
1
14
1
numbers must be in the order shown
(b)
electrons have a very small mass compared to protons
1
(c)
electrolysis of molten aluminium oxide
1
[4]
M3.
(a)
4
1
(b)
9
1
[2]
M4.
(a)
(i)
element
1
(ii)
compound
1
(b)
an / one electron from the sodium atom
1
is lost / transferred to form a sodium ion
1
(c)
(i)
8 electrons drawn on outer
energy level / shell
Page 29
1
(ii)
because oppositely charged ions attract each other
or
because chloride ions are negative and sodium ions are positive
1
[6]
M5.
(i)
two
or 2
1
(ii)
magnesium and chloride
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
•
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]
M6.
(a)
all three lines correct gains 2 marks
one or two correct gains 1 mark
if there are more than 3 lines then lose mark for each extra line
2
Page 30
(b)
(i)
covalent
1
(ii)
four
1
(iii)
hard
1
(iv)
three
1
(v)
soft
1
(c)
carbon
accept C
1
[8]
M7.
(a)
CH4
4 should be below halfway up H / tail of 4 below the dotted line
1
(b)
molecule
1
(c)
covalent
1
[3]
M8.
(a)
C3H8
capital letters for symbols numbers must be halfway or lower down
the element symbol
allow H8C3
do not allow 3:8 or C3 and H8
1
(b)
(i)
electron
1
(ii)
covalent
1
(c)
low and small
both for 1 mark
1
[4]
M9.
(a)
metals
1
(b)
copper atoms are arranged in layers
1
copper atoms can slide over each other.
1
(c)
the layers of atoms are distorted in bronze
1
[4]Page
31
M10.
(a)
atoms
1
(b)
mixture
1
metal
1
structure
1
smart
1
M11.
(a)
(i)
small or few atoms thick or size in the range 1–100 nanometres
owtte
1
(ii)
sensible idea of passing through smaller gaps owtte
eg can pass through skin / pores / cells or more easily absorbed
1
(b)
any two from:
•
good at absorbing UV light / radiation
•
spread more easily
•
cover better
•
save money / use less
•
transparent
•
less chance of getting skin cancer or stops skin cancer
ignore more effective alone
2
(c)
toxic to (cells / specific cells)
allow harm / damage / kill or cause cancer
1
Page 32
M12.
(a)
1 mark each, in these positions only
3
(b)
4
1
(c)
A
1
[5]
M13.
(a)
Cu
1
Fe
1
Zn
1
(b)
one significant use for each metal
do not credit vague answers such as ‘in experiments’ and 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
Page 33
•
stills or cooking utensils
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
(c)
any three 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
Page 34
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
(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]
M14.
(a)
covalent
1
(b)
(i)
liquid
1
(ii)
fluorine
accept F / F2
do not accept fluoride
1
M15.
(a)
(i)
gives out a large amount of energy
1
only water produced / product is non polluting (owtte)
allow it does not harm the environment
1
(ii)
does not explode / burst into flames owtte
ignore will not react
1
(iii)
hydrogen absorbed and released much faster
allow more efficient
allow can store a larger amount
1
Page 35
(b)
(i)
B
1
(ii)
a lithium atom loses an electron
1
(iii)
C
1
(c)
reversible
1
(d)
(i)
much smaller
1
(ii)
surface area
1
[10]
M16.
(a)
(i)
1
(ii)
nucleus
1
(b)
it has 2 more neutrons or converse
or
O-16 has 8 neutrons (1 mark)
O-18 has 10 neutrons (1 mark)
2
[4]
M17.
(i)
B or 2, 8, 1
for one mark
1
(ii)
A or 2, 8
for one mark
1
[2]
Page 36
M18.
(a)
Group 2 / Alkaline Earth Metals
for 1 mark
1
(b)
(i)
MgCl2/Mg2+ (Cl–)2
(or equation with correct answer)
for 1 mark
1
(ii)
ionic / electrovalent
for 1 mark
1
[3]
M19.
(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
Page 37
do not credit ‘chlorine ions’ but
allow this error to be carried forward
1
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]
M20.
(a)
bonding pair in the overlap and 6 other electrons arranged around the chlorine
must have either circles or symbols
need not be pairs but must not be in the overlap region
accept without H and Cl if clear
accept all x’s or all o’s
1
(b)
H2
+
Cl2
→
2HCl
accept multiples or fractions
accept correct formulae but not balanced for 1 mark
correctly balanced equation containing
‘correct’ lower / upper case symbols gets 1 mark
2
Page 38
(c)
MgCl2
accept Mg2+(Cl )2
‑
1
(d)
because magnesium chloride is made of ions or is ionic
accept there are strong forces of attraction between the ions /
particles in MgCl2 or strong electrostatic attractions
accept more energy to separate particles in MgCl2
do not accept MgCl2 molecules
do not accept reference to breaking bonds
1
hydrogen chloride is made of molecules or is covalent
accept there are only weak forces of attraction (between the
particles / molecules) in HCl
do not accept weak covalent bonds
do not accept reference to breaking bonds
do not accept MgCl2 is a solid and HCl is a gas
1
[6]
Page 39
C2.3 Analysis and Quantitative Chemistry Markscheme - Foundation
M1.
(a)
56g
for 1 mark
1
(b)
44 tonnes
for 1 mark
1
[2]
M2.
(i)
160
ignore units
1
(ii)
112
ignore units
1
(iii)
70
do not carry forward errors
1
[3]
M3.
(a)
N2O
1
(b)
13.8 to 14
gains full marks without working
if answer incorrect
13 gains 1 mark
or
14/101 × 100 gains 1 mark
2
[3]
M4.
(a)
152 correct answer with or without working = 2 marks
56 + 32 + (4 ×16) gains 1 mark
ignore any units
2
(b)
152g(rams)
ecf from the answer to (a) and g
must have unit g / gram / gramme / grams etc
accept g / mol or g per mole or g mole–1 or g/mol or g per mol or g
mol–1
do not accept g m
do not accept G
1
(c)
76(g)
ecf from their answer to (a) or (b) divided by 2
ignore units
1
[4]
Page 40
M5.
(a)
157
correct answer with or without working
(2 × 19 + 119) for 1 mark only
allow (119 + 19 =) 138 for 1 mark only
ignore units
2
(b)
24.2
accept answers in the range 24 to 24.2038.....
ignore incorrect rounding after correct answer
25 only without working gains 1 mark or
38/157 × 100 gains 1 mark or
(19/157 × 100 =) 12 to 12.1 gains 1 mark
allow error carried forward from part(a)
38/(a) × 100 gains 2 marks if calculated correctly
(19/138 × 100 =) 13.8 gains 1 mark
2
(c)
0.29
accept answers in the range 0.28 to 0.3
allow error carried forward from part (b)
(b)/100 × 1.2 correctly calculated
ignore units
1
(d)
an electron
allow electrons
allow electron shared / lost for 1 mark
apply list principle for additional particles
1
is gained owtte
must be linked to electron
accept can hold / take in if in correct context
eg it can hold another electron (in its outer shell) = 2 marks
it can take an electron (from another atom) = 2 marks
1
M6.
(i)
any two from:
•
A has four colours(*)
•
B has three colours(*)
(*) if first two bullets not stated
accept A has more colours (than B) or B has less colours (than A)
for 1 mark only
•
A / B have two colours the same
•
B has one different colour
2
(ii)
chromatography
1
[3]
Page 41
M7.
drinks / colours B and C are safe
1
drinks / colours A and D are not safe
accept a pair of one safe colour and one not safe colour identified
for 1 mark
accept A, B, C and D all contain one safe colour for 1 mark
ignore references to shading
1
[2]
M8.
(a)
check if safe to eat / healthy
or
permitted
accept references to allergies / medical problems
1
(b)
any three from:
accept dye for colour
•
made up of two colours / dots
•
contains an unknown colour / dot
•
contains a harmful colour
•
contains E104 / quinoline yellow
or does not contain E133 / brilliant blue
•
further analysis needed
3
(c)
ignore No or Yes but No must be implied
there could be other additives (in the sweets)
accept any other type of additives but not colourings
1
could still contain / use / add natural colours
accept non-artificial for natural
or
named natural colours
1
[6]
Page 42
M9.
(a)
(i)
column
1
(ii)
mass spectrometer
1
(b)
(i)
165
if answer is not correct then evidence of correct working gains
one mark.
e.g. (10 × 12) + 15 + 14 + 16
2
(ii)
10.37%
accept 10 / 10.4 / 10.37...............
if answer is not correct then evidence of correct working gains
one mark.
e.g. minimum evidence would be 14/135
2
(c)
any two from:
•
faster
•
more accurate
•
detects smaller amounts
2
(d)
to avoid bias
accept to check / compare the result
1
to improve reliability
1
[10]
Page 43