GCSE CHEMISTRY Sample Assessment Materials 1
For teaching from 2016
For award from 2018
GCSE (9-1) CHEMISTRY
SAMPLE ASSESSMENT
MATERIALS
This draft qualification has not yet been accredited by Ofqual. It is published to enable
teachers to have early sight of our proposed approach to GCSE Chemistry. Further
changes may be required and no assurance can be given at this time that the proposed
qualification will be made available in its current form, or that it will be accredited in time for
first teaching in September 2016 and first award in 2018.
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GCSE CHEMISTRY Sample Assessment Materials 3
Contents
Page
Component 1: Concepts in Chemistry
Foundation Tier: Sample Paper
Marking Scheme
5
39
Summary of marks allocated to assessment objectives
55
Higher Tier:
57
85
Sample Paper
Marking Scheme
Summary of marks allocated to assessment objectives
101
Component 2: Applications in Chemistry
Foundation Tier: Sample Paper
Resource Booklet
Marking Scheme
103
119
122
Summary of marks allocated to assessment objectives
134
Higher Tier:
135
151
155
Sample Paper
Resource Booklet
Marking Scheme
Summary of marks allocated to assessment objectives
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165
GCSE CHEMISTRY Sample Assessment Materials 5
Candidate Name
Centre Number
Candidate Number
GCSE CHEMISTRY
COMPONENT 1
Concepts in Chemistry
FOUNDATION TIER
SAMPLE PAPER
(2 hours 15 minutes)
For Examiner’s use only
Question Maximum
Mark
Mark
Awarded
1
9
2
15
3
11
4
7
5
12
6
11
7
8
8
9
9
8
10
12
11
10
12
8
Total
120
ADDITIONAL MATERIALS
In addition to this examination paper you will need:
 a calculator
 a ruler
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen. Do not use correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet.
INFORMATION FOR CANDIDATES
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 9.
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GCSE CHEMISTRY Sample Assessment Materials 6
Answer all questions.
1.
(a)
Chromatography can be used to test if racehorses have been given drugs.
Urine samples from four horses, A–D, were tested to find out whether they
contained caffeine or paracetamol.
The following diagram shows the results obtained.
(i)
Give the letter of the horse, A, B, C or D, that had been given
paracetamol.
[1]
…………………………………
(ii)
Explain how the results show that none of the horses had been given
caffeine.
[1]
............................................................................................................................
............................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 7
(iii)
The Rf value can be used to identify a substance. Use the
following equation to calculate the Rf value of paracetamol.
[2]
Rf = distance moved by paracetamol
distance moved by solvent
Rf = ………………..
(b)
The diagram below shows the laboratory apparatus used to separate crude oil
into four fractions.
The table below shows properties of the four fractions collected.
Fraction
Boiling point
range (°C)
Colour of
fraction
Viscosity
(how runny)
at 20 °C
How it burns
1
20-100
colourless
runny
very easily with a clean
flame
2
100-150
pale yellow
fairly runny
easily with a clean
flame
3
150-200
yellow
quite thick
quite easily with a
yellow flame and some
smoke
4
200-250
dark yellow
thick
hard to burn and a very
smoky flame
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GCSE CHEMISTRY Sample Assessment Materials 8
Use the information in the table to answer parts (i) and (ii).
(i)
(ii)
Give the number (1, 2, 3 or 4) of the fraction:
[4]
I
which is darkest in colour
………………….
II
which is easiest to burn
………………….
III
which is easiest to pour
………………….
IV
with the biggest boiling range
……………….…
Underline the process industry uses to obtain fractions from crude oil.
[1]
neutralisation
polymerisation
cracking
fractional distillation
9
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GCSE CHEMISTRY Sample Assessment Materials 9
2.
(a)
Iron is extracted in the blast furnace. Iron ore, limestone, coke and hot air are
the raw materials.
(i)
Draw a line to link the raw material to its use in the blast furnace.
Raw material
iron ore
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Use
source of iron
limestone
act as a fuel
coke
remove impurities
hot air
source of oxygen
[3]
GCSE CHEMISTRY Sample Assessment Materials 10
(ii)
The symbol equation below shows one of the main reactions occurring
in the furnace.
Fe2O3 + 3CO
I
2Fe + 3CO2
Use the information above to complete the word equation for
the reaction.
[2]
………………... + ………...………..
Iron(III) oxide + carbon monoxide
II
(b)
Put a tick (√) in the box next to the term used to describe the
removal of oxygen from iron(III) oxide.
[1]
reduction
oxidation
combustion
decomposition
The graph below shows how the tensile strength of iron alloys changes with
the percentage of carbon present.
800
700
600
500
Tensile
400
strength (Mpa)
300
200
100
0
0
0.5
1
1.5
2
2.5
3
Percentage of carbon present (%)
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3.5
4
GCSE CHEMISTRY Sample Assessment Materials 11
(i)
Describe how the tensile strength changes as the percentage of
carbon present increases.
[2]
............................................................................................................................
............................................................................................................................
(ii)
The table below shows the percentage of carbon present in some iron
alloys.
Alloy of iron
Percentage of carbon present in the alloy (%)
wrought iron
0.1
mild steel
0.3
high-carbon steel
0.9
cast iron
3.7
A steel with high tensile strength is needed in building the frame for a
roof. Use the information in the table and the graph to name the alloy
which has the highest tensile strength.
[1]
.............................................................................
(c)
A student was asked to investigate what happens when grey iron filings are
added to copper(II) sulfate solution.
The apparatus was set up as shown below. The mass was recorded at the
start and again after one hour.
bung
blue copper sulfate solution
colourless solution
grey iron fillings solution
orange-brown solid
80.6 g
At start
(i)
I
After 1 hour
Name this type of reaction.
……………………….……………………..
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[1]
GCSE CHEMISTRY Sample Assessment Materials 12
II
Explain why this reaction takes place.
[2]
................................................................................................................
................................................................................................................
(ii)
Complete the balanced symbol equation for the reaction taking place.
[1]
Fe + CuSO4
(iii)
........................ + .........................
Put a circle around the statement which describes the mass of the
beaker and contents after 1 hour.
mass of beaker + contents < 80.6 g
mass of beaker + contents = 80.6 g
mass of beaker + contents > 80.6 g
mass of beaker + contents = 40.3 g
Give a reason for your choice.
[2]
............................................................................................................................
15
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GCSE CHEMISTRY Sample Assessment Materials 13
3.
(a)
The diagrams below show the electronic structures of a magnesium atom and
an oxygen atom.
magnesium atom
oxygen atom
Magnesium reacts with oxygen to form magnesium oxide.
State, in terms of electrons, what happens to magnesium and oxygen atoms
during this reaction.
[2]
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
(b)
The key below represents atoms of some elements.
(i)
(ii)
Use the key to draw a diagram representing a molecule of nitrous
oxide, N2O.
[1]
Use the key to give the chemical formula for the compound
represented by the following diagram.
[1]
formula ............................
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GCSE CHEMISTRY Sample Assessment Materials 14
(c)
The box below shows the symbols and formulae for some gases.
CO2
(i)
O2
He
CH4
Ne
Choose two elements from the box above.
............... and .................
(ii)
(d)
(i)
(ii)
SO2
[1]
Choose two compounds from the box above.
............... and .................
[1]
Give the formulae of the:
[2]
positive ion in potassium chloride
................
negative ion in Na2O
................
Give the chemical formula for magnesium hydroxide.
[1]
.................................................................................
(e)
Sodium chlorate, NaClO3, is used to bleach paper.
Calculate the relative formula mass (Mr) of sodium chlorate.
[2]
Mr = ...................
11
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GCSE CHEMISTRY Sample Assessment Materials 15
4.
(a)
Methanol and ethanol are both fuels. A group of students were asked to carry
out an experiment to find out which was the better fuel. The apparatus they
used is shown in the following diagram and their results are recorded in the
table below.
Methanol
Ethanol
Mass of spirit burner and fuel before heating (g)
140.5
136.8
Mass of spirit burner and fuel after heating (g)
140.0
136.3
Volume of water used (cm3)
100
100
Temperature of water before heating (oC)
20
21
Temperature of water after heating (oC)
25
29
(i)
State which is the better fuel and give a reason for your answer.
[1]
............................................................................................................................
............................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 16
(ii)
Their teacher said that burning these amounts of fuels would have
given off enough heat for the water to reach much higher
temperatures.
Suggest two possible reasons why higher temperatures were not
reached.
[2]
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
(iii)
Complete and balance the symbol equation for the combustion of
methanol.
[2]
2CH3OH + 3O2
(b)
(i)
......................... + .........................
The following diagram shows the structural formula of ethanol.
H
H
H
C
C
H
H
O
H
Give the molecular formula of ethanol. .......................................... [1]
(ii)
An alcohol contains three carbon atoms, eight hydrogen atoms and
one oxygen atom. Draw the structural formula of an alcohol with this
number of atoms.
[1]
7
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GCSE CHEMISTRY Sample Assessment Materials 17
5.
(a)
Alloys and composites are synthetic materials produced for a huge range of
uses.
State whether the statements listed below relate to alloys or composites.
Circle your answer (alloy or composite) in each case.
Statement
(b)
[2]
Answer
a mixture of two or more elements
alloy
composite
each component is easily recognised
alloy
composite
reinforced concrete
alloy
composite
bronze
alloy
composite
A common example of a composite material is fiberglass. This is made by
mixing glass fibres with a polymer resin such as epoxy resin.
Give one advantage of arranging the glass fibres as shown in the diagram
above.
[1]
............................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 18
(c)
The table below shows some properties of glass and epoxy resin.
(i)
Material
Density (g/cm3)
Strength (N/cm2)
glass
2.4
350 000
epoxy resin
1.5
6000
A fibre glass panel contains 3 cm3 of epoxy resin. Calculate the mass
of the resin.
[2]
Use the following equation:
mass = density × volume
mass = .......................... g
(ii)
A force of 52.5 N just breaks a glass fibre. Calculate the crosssectional area (csa) of the glass fibre.
[2]
Use the following equation:
force = strength  csa
cross-sectional area (csa) = .................................. cm2
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GCSE CHEMISTRY Sample Assessment Materials 19
(d)
The equation below shows the formation of the plastic polythene from ethene.
H
n
H
C
H
C
H
H
H
H
C
C
H
H
H
n
ethene
polyethene
Describe what happens to ethene molecules during the formation of
polythene.
[3]
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
(e)
The table below shows some information about monomers and the polymers
that can be made from them.
Complete the table.
Name of
monomer
[2]
Structural
formula of
monomer
F
C
tetrafluoroethene
F
vinylchloride
(chloroethene)
F
C
F
Name of polymer
Repeating unit
for the polymer
polytetrafluoroethene
PTFE
polyvinylchloride
PVC
H
H
H
C
C
H
Cl
H
n
12
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GCSE CHEMISTRY Sample Assessment Materials 20
6.
(a)
The pie charts below show how the present day atmosphere on Earth
compares with the early atmosphere formed billions of years ago.
Early atmosphere
Today's atmosphere
sulfur
dioxide
3%
other
2%
nitrogen
5%
oxygen
21%
argon and
carbon
dioxide
1%
carbon
dioxide
90%
nitrogen
78%
(i)
Use the information in the pie charts to describe how today’s
atmosphere is different from the early atmosphere.
[3]
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
(ii)
Use the information in the diagram to describe how volcanoes
contributed to the appearance of oxygen in the atmosphere.
[2]
............................................................................................................................
............................................................................................................................
............................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 21
(b)
The following graph shows how the concentration of carbon dioxide in the
Earth’s atmosphere changed between 1750 and the year 2000.
(i)
Describe the change in the pattern shown in the graph before and
after 1900.
Explain what caused the change.
[3]
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
(ii)
Explain how the change in concentration of carbon dioxide is believed
by most scientists to be causing sea levels to rise.
[3]
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
11
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GCSE CHEMISTRY Sample Assessment Materials 22
7.
(a)
The graph below shows the total annual sulfur dioxide emissions in the UK
between 1970 and 2012. International targets for sulfur dioxide levels are
also shown ().
(i)
Use the information to give two conclusions relating to sulfur dioxide
emissions in the UK between 2000 and 2012.
[2]
............................................................................................................................
………................................................................................................................
(ii)
The generation of electricity in power stations is the main source of
sulfur dioxide.
Suggest an explanation for the small peak in sulfur dioxide emissions
in 1979.
[2]
............................................................................................................................
………................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 23
(b)
One of the major consequences of sulfur dioxide emission is the formation of
acid rain. Acid rain causes the pH in lakes and reservoirs to decrease.
The graph below shows how the pH of a reservoir changed between 1982
and 2005.
(i)
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Describe how the pH and the acidity changed between 1982 and
2005.
[2]
pH
..............................................................................
Acidity
..............................................................................
GCSE CHEMISTRY Sample Assessment Materials 24
(ii)
The reservoir is in a remote part of the country and difficult to reach.
pH readings were taken daily and used to produce the graph above.
Give the letter of the equipment above that you would choose to
record and store the pH of the reservoir several times a day. Give a
reason for your choice.
[2]
Letter
......................
Reason ………………...........................................................................
……........................................................................................................
8
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GCSE CHEMISTRY Sample Assessment Materials 25
8.
(a)
One method of preparing dry copper(II) sulfate crystals is by reacting a
carbonate with a dilute acid. The information below shows the stages a pupil
follows to make copper(II) sulfate crystals.
(i)
Name the acid used in the process.
[1]
............................................................................................................................
(ii)
Name gas A formed in stage 1.
[1]
...........................................................................................................................
(iii)
Name the substance removed during stage 3.
[1]
............................................................................................................................
(b)
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The blue colour of hydrated copper(II) sulfate crystals is due to the presence
of water molecules. These water molecules can be removed by gently heating
to form white anhydrous copper(II) sulfate powder using the apparatus shown
below.
GCSE CHEMISTRY Sample Assessment Materials 26
6.25 g of blue hydrated copper(II) sulfate was gently heated in a crucible until
the mass remaining was a constant 4.00 g.
(i)
Calculate the mass of water removed during heating.
[1]
mass of water = ....................... g
(ii)
Use the equation below to calculate the percentage of water in the
blue copper(II) sulfate.
[2]
percentage of water in blue copper(II)sulfate 
mass of water
× 100
mass of blue copper(II)sulfate
percentage of water = ............................... %
(iii)
The equation below represents the reaction taking place.
CuSO4.5H2O
CuSO4
+
5H2O
State and explain what you would expect to see if water were added
to the white anhydrous copper(II) sulfate powder.
[3]
...........................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
9
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GCSE CHEMISTRY Sample Assessment Materials 27
9.
A small amount of an element was heated and its temperature was recorded over a
period of 12 minutes. At room temperature the element is a solid. The results are
shown on the grid below.
(a)
Use the information above to answer parts (a) and (b).
1400
1200
1000
800
Temperature (oC)
600
400
200
0
0
(i)
2
4
10
Give the melting point and boiling point of the element.
melting point = ..…….….oC
(ii)
6
8
Time (min)
12
14
[1]
boiling point = ……...…oC
State whether the element is a metal or a non-metal . Give the reason
for you choice.
[1]
……………………………………………...…………..………………………………
……………………………………………...…………..………………………………
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GCSE CHEMISTRY Sample Assessment Materials 28
(b)
Describe and explain, using particle theory, the changes that occur to the
element when it is heated over the period of the first 12 minutes.
[6 QER]
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
.......................................................................................................................................
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8
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GCSE CHEMISTRY Sample Assessment Materials 29
10.
(a)
Complete the following table that shows information about atoms of some
elements.
[5]
Element
Symbol
Number of
protons
Number of
neutrons
Number of
electrons
4
5
4
9
……………
…………….
20
20
…………….
…………….
22
18
9
Be
beryllium
4
19
F
fluorine
9
calcium
……………..
40
Ar
argon
(b)
18
The diagram below shows the electronic structure of an element in the
Periodic Table.
Using X to represent an electron, draw a similar diagram to show the
electronic structure of the element which:
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(i)
lies directly below this element in the Periodic Table;
[1]
(ii)
lies directly to the right of this element in the Periodic Table.
[1]
GCSE CHEMISTRY Sample Assessment Materials 30
(c)
The diagram below shows the early form of the Periodic Table developed by
Mendeleev.
I
H
1.01
II
III
IV
V
VI
VII
Li
6.94
Be
9.01
B
10.8
C
12.0
N
14.0
O
16.0
F
19.0
Na
23.0
Mg
24.3
Al
27.0
Si
28.1
P
31.0
S
32.1
Cl
35.5
K
39.1
Ca
40.1
Cu
63.5
Rb
85.5
Ti
47.9
Zn
65.4
Sr
87.6
Ag
108
Ce
133
V
50.9
As
74.9
Y
88.9
Cd
112
Ba
137
Au
197
Zr
91.2
In
115
Nb
92.9
Sn
119
La
139
Hg
201
Ti
204
Pb
207
Mn
54.9
Se
79.0
Sb
122
Te
128
W
184
Fe
55.9
Co
58.9
Ni
58.7
Ru
101
Rh
103
Pd
106
Os
194
Ir
192
Pt
195
Br
79.9
Mo
95.9
Ta
181
Th
232
(i)
Cr
52.0
VIII
I
127
Bi
209
U
238
State what information Mendeleev used to arrange the elements.
[2]
............................................................................................................................
............................................................................................................................
............................................................................................................................
(ii)
Describe and explain the differences between Period 4 of Mendeleev's
table and that of the modern table.
[3]
............................................................................................................................
............................................................................................................................
...........................................................................................................................
12
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GCSE CHEMISTRY Sample Assessment Materials 31
11.
A pupil investigated how the temperature changes when dilute hydrochloric acid
reacts with dilute sodium hydroxide solution.
thermometer
conical flask
25 cm3 sodium hydroxide solution
(a)
80 cm3 of dilute acid was added, 10 cm3 at a time, to 25 cm3 of alkali in a
conical flask. The highest temperature reached was recorded each
time.
The table below shows the results obtained.
(i)
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Volume of acid added
(cm3)
Temperature
(oC)
0
21.0
10
22.8
20
24.2
30
25.4
40
26.4
50
27.0
60
26.7
70
26.2
80
25.6
Use the grid provided on the next page to plot the volume of acid
added against temperature.
Add a suitable line.
[4]
GCSE CHEMISTRY Sample Assessment Materials 32
28
27
Temperature (oC)
26
25
24
23
22
21
2020
00
10
(ii)
20
30
40
50
3
Volume of acid (cm )
60
Describe and explain the shape of the graph in relation to the
chemical reaction taking place.
70
80
[3]
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 33
(b)
(i)
Apart from measuring the change in temperature, state a different
method that could be used to show the stages of this reaction.
[1]
………………………………………………………………………………………….
(ii)
Explain how your new method would show the stages of the reaction.
[2]
………………………………………………………………………………………….
………………………………………………………………………………………….
10
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GCSE CHEMISTRY Sample Assessment Materials 34
12.
(a)
The electrolysis of water can be used to form hydrogen on an industrial scale.
The overall equation for the electrolysis of water is:
2H2O
(i)
2H2
+
O2
Using the formula below calculate the atom economy for the
production of hydrogen.
Ar(H) = 1
[2]
Ar(O) = 16
% atom economy =
mass of desired product x100
total mass of all reactant(s)
atom economy = …….. %
(ii)
Explain how the atom economy calculated in a(i) supports the
reason for not using the electrolysis of water as the main
method for the industrial preparation of hydrogen.
[2]
………………………………………………………………………………………….
..……………………………………………………………..………………………….
………………………………………………………………………………………….
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GCSE CHEMISTRY Sample Assessment Materials 35
(b)
The graph below shows the total mass of oxygen formed over 10 minutes.
1.6
1.4
1.2
1
Mass of oxygen 0.8
(g)
0.6
0.4
0.2
0
0
2
4
6
8
10
Time (min)
Draw a second line on the grid to show the mass of hydrogen that you
would expect to be collected during the same 10 minutes.
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[2]
GCSE CHEMISTRY Sample Assessment Materials 36
(c)
Use only information from the table below to explain two advantages of using
hydrogen as a fuel for cars.
[2]
Raw material
water
Extraction method
electrolysis
Combustion product(s)
water
State at room temperature and pressure
gas
Storage
thick steel containers
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8
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GCSE CHEMISTRY Sample Assessment Materials 37
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GCSE CHEMISTRY Sample Assessment Materials 38
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GCSE CHEMISTRY Sample Assessment Materials 39
COMPONENT 1 - Concepts in Chemistry
FOUNDATION TIER
MARK SCHEME
GENERAL INSTRUCTIONS
Recording of marks
Examiners must mark in red ink.
One tick must equate to one mark (apart from the questions where a level of response mark scheme is applied).
Question totals should be written in the box at the end of the question.
Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.
Marking rules
All work should be seen to have been marked.
Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.
Crossed out responses not replaced should be marked.
Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.
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GCSE CHEMISTRY Sample Assessment Materials 40
Extended response question
A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly,
decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality of the
response. Then decide which mark to award within the level. Award the higher mark in the level if there is a good match with both the
content statements and the communication statements.
Marking abbreviations
The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded.
cao
ecf
bod
=
=
=
© WJEC CBAC Ltd.
correct answer only
error carried forward
benefit of doubt
GCSE CHEMISTRY Sample Assessment Materials 41
Question
1
(a)
(b)
Marking details
C
caffeine ‘spot’ not present in urine samples
Distance moved by paracetamol is 3 (1)
0.3 (1)
Correct answer with no working (2)
(i)
(ii)
(iii)
(i)
(ii)
I
II
III
IV
4
1
1
1
fractional distillation
AO1
AO2
1
Marks Available
AO3
Total
1
1
1
Maths
Prac
1
1
2
0
4
1
1
2
1
1
1
1
1
1
1
1
1
1
Question 1 total
© WJEC CBAC Ltd.
2
2
5
9
GCSE CHEMISTRY Sample Assessment Materials 42
Question
2
(a)
(i)
(ii)
(b)
Marking details
Line connecting points as follows:
iron ore ……………source of iron
limestone ………….remove impurities
coke …………………fuel / forms carbon monoxide
hot air ………………..source of oxygen
All four correct 3 marks
Any two correct 2 marks
Any one correct 1 mark
I
II
(i)
Iron (1) Carbon dioxide (1)
Reduction
It increases up to 0.8% carbon then decreases (2)
AO1
AO2
Marks Available
AO3
Total
3
3
2
1
2
1
2
2
Maths
Prac
2
If not awarded, credit (1) for increases then decreases
(c)
(ii)
(i)
I
II
high-carbon steel
Displacement reaction (1)
Iron reacts with copper(II) sulfate to form iron(II) sulfate/copper
(1)
Iron is more reactive than copper (1)
(ii)
FeSO4 and Cu – both needed
(iii)
= 80.6 g (1)
Mass has not left or entered the beaker / same number of atoms
in the beaker (1)
Question 2 total
© WJEC CBAC Ltd.
1
1
1
1
1
1
1
2
1
2
1
1
1
1
2
8
4
2
3
15
4
4
GCSE CHEMISTRY Sample Assessment Materials 43
Question
3
(a)
(i)
Marking details
AO1
Magnesium atom loses two electrons (1)
Oxygen atom gains two electrons (1)
AO2
Marks available
AO3
Total
2
2
1
1
1
1
Maths
Prac
If not awarded, credit (1) for magnesium loses electrons and
oxygen gains electrons
(b)
(c)
(d)
(i)
(ii)
NH3
Accept H3N
(i)
Any two from O2 / He / Ne
1
1
(ii)
Any two from CO2 / CH4 / SO2
1
1
(i)
K+ (1)
O2‒ (1)
(ii)
Mg(OH)2
23 + 35.5 + 3(16) (1)
106.5 (1)
Correct answer only 2 marks
(e)
Question 3 total
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2
1
1
1
2
2
2
2
11
2
9
1
0
0
GCSE CHEMISTRY Sample Assessment Materials 44
Question
4
(a)
(i)
(ii)
Marking details
AO1
AO2
Ethanol is the better fuel because it gives the greater
temperature rise
(b)
(i)
Maths
Prac
1
1
1
2
2
2
Some heat escaped to the room (1)
Second mark for any of following (1)
Heat absorbed by beaker
Heat escaped because there is no lid
Heat escaped through beaker
(iii)
Marks available
AO3
Total
Both formulae correct – CO2 and H2O (1)
1
Correctly balanced - 2CO2 + 4H2O (1)
Must have correct formulae for this mark to be awarded
1
2
C2H5OH
1
1
1
1
1
(ii)
H
H
H
OH
C
C
C
H
H
H
Question 4 total
© WJEC CBAC Ltd.
H
or
H
H
OH
H
C
C
C
H
H
H
H
1
3
3
7
1
3
GCSE CHEMISTRY Sample Assessment Materials 45
Question
5
(a)
Marking details
AO1
AO2
Marks available
AO3
Total
Maths
Prac
alloy
composite
composite
alloy
(b)
(c)
(i)
(ii)
(d)
All four correctly circled (2)
Any two correctly circled (1)
2
2
Gives a stronger material
1
1
Mass = 1.5 × 3 (1)
Mass = 4.5 (1)
Correct answer with no working (2)
1
csa = 52.5/350 000 (1)
csa = 0.00015 (or 1.5 x 10-4) (1)
Correct answer with no working (2)
C=C bond opens (1)
Ethene molecules / monomers join together (1)
Long chain / polymer forms (1)
1
2
2
1
1
2
2
3
3
(e)
F
F
2
H
(1)
Question 5 total
© WJEC CBAC Ltd.
C
C
F
F
2
H
(1)
7
5
0
12
4
0
GCSE CHEMISTRY Sample Assessment Materials 46
Question
6
(a)
(i)
(ii)
Marking details
Amount of carbon dioxide / sulfur dioxide has decreased (1)
Amount of nitrogen has increased (1)
Contains oxygen / amount of oxygen has increased (1)
AO1
(i)
(ii)
© WJEC CBAC Ltd.
Marks available
AO3
Total
3
Maths
Prac
3
Volcanoes released carbon dioxide [and water] (1)
Plants used carbon dioxide during photosynthesis producing
oxygen (1)
(b)
AO2
2
2
Gradual increase in carbon dioxide before 1900 (1)
Large increase in carbon dioxide after 1900 (1)
Increased industrialisation / huge increase in amount of fossil
fuels burned (1)
1
3
Increasing / changing concentration increases greenhouse effect
/ global warming (1)
Increases mean atmospheric temperature (1)
Increases mass of polar ice melting (1)
3
3
Question 6 total
7
2
2
2
2
11
2
0
GCSE CHEMISTRY Sample Assessment Materials 47
Question
7
(a)
(i)
(ii)
(b)
(i)
(ii)
© WJEC CBAC Ltd.
Marking details
AO1
AO2
Emissions decreasing (1)
Levels below international targets (1)
More electricity generated (1)
Sensible explanation e.g. cold winter therefore more electricity
used for heating (1)
Marks available
AO3
Total
2
2
1
2
Maths
Prac
1
pH increased (1)
Acidity decreased (1)
1
B (1)
Can record data several times over a period of time /
continuously (1)
1
1
Question 7 total
3
1
2
2
2
3
8
2
0
2
GCSE CHEMISTRY Sample Assessment Materials 48
Question
8
(a)
(b)
Marking details
AO1
1
(i)
Sulfuric acid
(ii)
Carbon dioxide
1
(iii)
(i)
(ii)
Water
2.25
2.25 × 100 (1)
6.25
1
© WJEC CBAC Ltd.
Prac
1
1
1
1
1
1
1
1
1
2
1
36 (1) Allow ecf
(iii)
Marks available
AO3
Total
Maths
1
AO2
Turns blue (1)
Water bubbles / boils / reacts exothermically (1)
Copper(II) sulfate is rehydrated / recombines with water (1)
3
Question 8 total
7
2
3
2
0
9
2
3
2
9
GCSE CHEMISTRY Sample Assessment Materials 49
Question
9
(a)
(i)
(ii)
(b)
Marking details
m.p. 100oC and b.p. 880oC Both needed for (1)
Metal
Explanation high melting point and high boiling point
Both needed for (1)
Indicative content:
We start with a solid in which particles are closely packed and
fixed in place. (AO1)
Time 0-1 min - As temp. increases vibrations increase but the
particles cannot break free of each other (AO2)
Between 1-5 min the energy supplied allows particles to break
free from a rigid structure - the substance is melting (AO2)
In a liquid, particles are still close packed but are no longer in a
fixed structure and can move around (AO1)
Between 5-8 min we have a liquid. (AO2) in which the particles
gain more and more energy and move faster but remain close
together (AO1)
Between 8-12 min the energy is supplied to overcome forces of
attraction between particles. The element is boiling. (AO2)
The particles break free of each other forming a gas in which
particles are widely spaced. (AO1)
5 ─ 6 marks: Accurately describes solids, liquids and gases
using particle theory. States energy is absorbed when
substance melts or boils. Explains what is happening to particles
in each region of the graph using particle theory.
There is a sustained line of reasoning which is coherent,
substantiated and logically structured. The information included
in the response is relevant to the argument.
© WJEC CBAC Ltd.
AO1
3
1
Marks available
AO3
Total
Maths
1
1
1
1
3
6
AO2
Prac
GCSE CHEMISTRY Sample Assessment Materials 50
3 ─ 4 marks: Describes in some detail solids, liquids and gases
using particle theory. Understands energy is needed for melting
and boiling. Explains what is happening to particles in (at least)
the regions of the graph where melting or boiling is occurring
using particle theory.
There is a line of reasoning which is partially coherent,
supported by some evidence and with some structure. Mainly
relevant information is included in the response but there may
be some minor errors or the inclusion of some information not
relevant to the argument.
1 ─ 2 marks: Basic description of solids, liquids and gases.
Recognises energy is needed to bring about a state change
There is a basic line of reasoning which is not coherent,
supported by limited evidence and with very little structure.
There may be significant errors or the inclusion of information
not relevant to the argument.
0 marks: No attempt made or no response worthy of credit.
Question 9 total
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3
4
1
8
1
0
GCSE CHEMISTRY Sample Assessment Materials 51
Question
10
Marking details
AO1
AO2
Marks available
AO3
Total
Maths
5
5
1
1
1
1
(a)
10 (1)
40
Ca (1)
20
(b)
18 (1)
9 (1)
20 (1)
(i)
(ii)
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Prac
GCSE CHEMISTRY Sample Assessment Materials 52
Question
(c)
(i)
(ii)
© WJEC CBAC Ltd.
Marking details
Atomic weights (1)
Patterns of reactivity (1)
AO1
AO2
Marks available
AO3
Total
2
2
K and Cu occupy their own spaces–have different properties
(1)
Gaps filled – new elements discovered (1)
Additional group – noble gases discovered (1)
Transition metals placed together – have similar properties
(1)
3
3
Question 10 total
5
Maths
Prac
0
0
Any three of the following
Must have explanation as well as observation
7
0
12
GCSE CHEMISTRY Sample Assessment Materials 53
Question
11
(a)
(i)
(ii)
(b)
© WJEC CBAC Ltd.
(i)
(ii)
Marking details
Scales: Both axes
Plotting: All correct
Any 8 correct (1)
Line:
Smooth curve through all points
Judgement by eye
AO1
(1)
(2)
AO2
4
Marks available
AO3
Total
4
Maths
4
Prac
(1)
Graph rises as acid and alkali react / exothermic reaction (1)
Peak / no further increase – point at which neutralisation is
complete / alkali used up (1)
Graph falls – cooling to room temperature as no further
reaction takes place / cool acid continues to be added (1)
3
pH / universal indicator
Colour change as acid added (1)
Description of colour change (1)
e.g. purple to green to red
1
2
Question 11 total
3
4
3
3
3
1
2
1
2
10
4
6
GCSE CHEMISTRY Sample Assessment Materials 54
Question
12
(a)
(i)
(ii)
(b)
(c)
Marking details
11.1 (2)
AO1
4/36 x 100
Award (1) for 4/36
Allow ecf
Low atom economy (1) and any one for (1):
Not efficient process/
Not economic process/
Not a ‘green’ process /
O2 is a waste product …
Straight line from (0,0) of lower gradient (1)
Line to 0.2 g after 10 minutes) (1)
raw material is water …renewable natural resource (1)
AO2
1
1
Marks available
AO3
Total
2
Maths
2
Prac
2
2
2
2
2
2
2
4
8
4
2
2
combustion product is water ….does not contribute to global
warming (1)
Question 12 total
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0
4
GCSE CHEMISTRY Sample Assessment Materials 55
COMPONENT 1 - Concepts in Chemistry
FOUNDATION TIER
SUMMARY OF MARKS ALLOCATED TO ASSESSMENT OBJECTIVES
Question
AO1
AO2
AO3
TOTAL MARK
MATHS
PRAC
1
2
2
5
9
0
4
2
8
4
3
15
4
4
3
2
9
0
11
2
0
4
1
3
3
7
1
3
5
7
5
0
12
4
0
6
7
2
2
11
2
0
7
3
2
3
8
0
2
8
7
2
0
9
2
9
9
3
4
1
8
1
0
10
5
7
0
12
0
0
11
3
4
3
10
4
6
12
0
4
4
8
4
2
TOTAL
48
48
24
120
24
30
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 57
Candidate Name
Centre Number
Candidate Number
GCSE CHEMISTRY
COMPONENT 1
Concepts in Chemistry
HIGHER TIER
SAMPLE PAPER
(2 hours 15 minutes)
For Examiner’s use only
Question Maximum
Mark
Mark
Awarded
1
12
2
10
3
8
4
12
5
14
6
9
7
8
8
20
9
10
10
11
11
6
Total
120
ADDITIONAL MATERIALS
In addition to this examination paper you will need:
 a calculator
 a ruler
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen. Do not use correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet.
INFORMATION FOR CANDIDATES
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 11.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 58
Answer all questions.
1.
(a)
Complete the following table that shows information about atoms of some
elements.
[5]
Element
Symbol
Number of
protons
Number of
neutrons
Number of
electrons
4
5
4
9
……………
…………….
20
20
…………….
…………….
22
18
9
Be
beryllium
4
19
F
fluorine
9
calcium
……………..
40
Ar
argon
(b)
18
The diagram below shows the electronic structure of an element in the
Periodic Table.
Using X to represent an electron, draw a similar diagram to show the
electronic structure of the element which:
© WJEC CBAC Ltd.
(i)
lies directly below this element in the Periodic Table;
[1]
(ii)
lies directly to the right of this element in the Periodic Table.
[1]
GCSE CHEMISTRY Sample Assessment Materials 59
(c)
The diagram below shows the early form of the Periodic Table developed by
Mendeleev.
I
H
1.01
II
III
IV
V
VI
VII
Li
6.94
Be
9.01
B
10.8
C
12.0
N
14.0
O
16.0
F
19.0
Na
23.0
Mg
24.3
Al
27.0
Si
28.1
P
31.0
S
32.1
Cl
35.5
K
39.1
Ca
40.1
Cu
63.5
Rb
85.5
Ti
47.9
Zn
65.4
Sr
87.6
Ag
108
Ce
133
V
50.9
As
74.9
Y
88.9
Cd
112
Ba
137
Au
197
Zr
91.2
In
115
Nb
92.9
Sn
119
La
139
Hg
201
Ti
204
Pb
207
Mn
54.9
Se
79.0
Sb
122
Te
128
W
184
Fe
55.9
Co
58.9
Ni
58.7
Ru
101
Rh
103
Pd
106
Os
194
Ir
192
Pt
195
Br
79.9
Mo
95.9
Ta
181
Th
232
(i)
Cr
52.0
VIII
I
127
Bi
209
U
238
State what information Mendeleev used to arrange the elements.
[2]
............................................................................................................................
............................................................................................................................
............................................................................................................................
(ii)
Describe and explain the differences between Period 4 of Mendeleev's
table and that of the modern table.
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
12
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GCSE CHEMISTRY Sample Assessment Materials 60
2.
A pupil investigated how the temperature changes when dilute hydrochloric acid
reacts with dilute sodium hydroxide solution.
thermometer
conical flask
25 cm3 sodium hydroxide solution
(a)
80 cm3 of dilute acid was added, 10 cm3 at a time, to 25 cm3 of alkali in a
conical flask. The highest temperature reached was recorded each time.
The table below shows the results obtained.
(i)
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Volume of acid added
(cm3)
Temperature
(oC)
0
21.0
10
22.8
20
24.2
30
25.4
40
26.4
50
27.0
60
26.7
70
26.2
80
25.6
Use the grid provided on the next page to plot the volume of acid
added against temperature.
Add a suitable line.
[4]
GCSE CHEMISTRY Sample Assessment Materials 61
28
27
Temperature (oC)
26
25
24
23
22
21
2020
00
10
(ii)
20
30
40
50
3
Volume of acid (cm )
60
Describe and explain the shape of the graph in relation to the
chemical reaction taking place.
70
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
© WJEC CBAC Ltd.
80
GCSE CHEMISTRY Sample Assessment Materials 62
(b)
(i)
Apart from measuring the change in temperature, state a different
method that could be used to show the stages of this reaction.
[1]
……..……………………………………………………………………………………
(ii)
Explain how your new method would show the stages of the reaction.
[2]
…………………………………………………………………………………………..
…….…………………………………………………………………………………….
10
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GCSE CHEMISTRY Sample Assessment Materials 63
3.
(a)
The electrolysis of water can be used to form hydrogen on an industrial scale.
The overall equation for the electrolysis of water is:
2H2O
(i)
2 H2
+
O2
Using the formula below calculate the atom economy for the
production of hydrogen.
Ar(H) = 1
[2]
Ar(O) = 16
% atom economy =
mass of desired product x100
total mass of all reactant(s)
atom economy = …………..%
(ii)
Explain how the atom economy calculated in a(i) supports the
reason for not using the electrolysis of water as the main
method for the industrial preparation of hydrogen.
[2]
…………………………………………………………………………………………..
…………………………………………………………………………………………..
…………………………………………………………………………………………..
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GCSE CHEMISTRY Sample Assessment Materials 64
(b)
The graph below shows the total mass of oxygen formed over 10 minutes.
1.6
1.4
1.2
1
Mass of oxygen 0.8
(g)
0.6
0.4
0.2
0
0
2
4
6
8
10
Time (min)
Draw a second line on the grid to show the mass of hydrogen that you
would expect to be collected during the same 10 minutes.
[2]
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GCSE CHEMISTRY Sample Assessment Materials 65
(c)
Use only information from the table below to explain two advantages of using
hydrogen as a fuel for cars.
[2]
Raw material
water
Extraction method
electrolysis
Combustion product(s)
water
State at room temperature and pressure
gas
Storage
thick steel containers
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
8
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 66
4.
(a)
The graph below shows the production of copper between 1900 and 2015,
and the predicted production to 2020.
18
16
14
12
Production
6
(10 tonnes)
10
8
6
4
2
0
1900
1920
1940
1960
1980
2000
2020
Year
Suggest an explanation for the increase in copper production since the 1940s.
[1]
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
(b)
The traditional method of obtaining copper is to extract it from high grade
copper ore obtained from a copper mine.
Describe two problems with obtaining copper ore from copper mines.
[2]
........................................................................................................................................
........................................................................................................................................
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GCSE CHEMISTRY Sample Assessment Materials 67
(c)
The flow diagram below shows the steps taken in obtaining copper by the
process of phytomining.
Stage 1
(i)
Stage 2
Describe the role of the plant in Stage 1.
[1]
.............................................................................................................................
(ii)
Give the chemical name for the compound A.
[1]
.............................................................................................................................
(iii)
Explain three disadvantages of phytomining compared with traditional
mining.
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 68
(iv)
The ash obtained from Stage 2 can be reacted with sulfuric acid to
form aqueous copper(II) sulfate.
Describe and explain one method used to obtain copper metal from
aqueous copper(II) sulfate.
Include a balanced symbol equation in your answer.
[4]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
12
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 69
5.
(a)
Aluminium is extracted from molten aluminium oxide by electrolysis.
(i)
Complete the following electrode equations.
At the cathode: …….… + 3e‒
At the anode: 2O2‒ ‒ ….....
(ii)
[2]
Al
O2
State and explain how the production costs of aluminium are reduced.[4]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
(iii)
The overall equation for the extraction of aluminium is as follows.
2Al2O3
I
4Al + 3O2
Calculate how many tonnes of aluminium can be obtained from
2040 tonnes of aluminium oxide.
[3]
mass of aluminium = ............................... tonnes
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 70
II
Calculate the volume of oxygen in m3 that could be formed from
2040 tonnes of aluminium oxide. The volume of 1 mol of gas at
room temperature and pressure is 0.024 m3.
[3]
volume of oxygen = .................................... m3
(b)
Explain, in terms of the metallic bonding model, why aluminium:
(i)
conducts electricity;
[1]
…………………………………………………………………………………………
…………………………………………………………………………………………
(ii)
is malleable and ductile.
[1]
…………………………………………………………………………………………
…………………………………………………………………………………………
14
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 71
6.
(a)
A pupil used the following tests to identify unknown compounds A, B, C and
D.
These are described below as tests 1 to 5 but not necessarily in that order.
The charts show the results obtained for each compound.
cream precipitate
formed
Deduce which test is which and hence identify compounds A, B, C and D.
© WJEC CBAC Ltd.
A
.....................................................................................
B
.....................................................................................
C
.....................................................................................
D
.....................................................................................
[4]
GCSE CHEMISTRY Sample Assessment Materials 72
(b)
Sodium hydroxide solution can be used to detect the presence of aqueous
copper(II) ions.
(i)
The equation below represents the reaction occurring between
copper(II) chloride solution and sodium hydroxide solution.
CuCl2(aq) + 2NaOH(aq)
Cu(OH)2(s) + 2NaCl(aq)
Write the ionic equation for the reaction, including state symbols.
..................... + .....................
(ii)
[2]
......................................
When sodium hydroxide solution is added to iron(III) bromide solution,
FeBr3(aq), a brown precipitate is formed.
Write the balanced symbol equation for this reaction.
..................... + .....................
[3]
..................... + .....................
9
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 73
7.
Hydrogen sulfide (H2S) burns in air to give sulfur dioxide and water.
The following equation shows the rearrangement of atoms as hydrogen sulfide burns.
S
H
H
S
H
+
O
S
O O
O O
O O
O
S
O
H
O +
H
O
H
H
O
H
The relative energies of these bonds are given in the table below.
Bond
Bond energy (kJ)
H‒S
339
O=O
....................
S=O
523
O‒H
463
The overall relative energy change during the reaction is ‒1103 kJ, which shows that
the reaction is exothermic.
(a)
Use the information given above to calculate the energy needed to break the
O=O bond.
[5]
energy needed = .............................. kJ
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 74
(b)
Draw arrows (↕) on the reaction profile to show the activation energy (A) and
the overall energy change (B) for the burning of hydrogen sulfide.
[2]
Energy
(kJ)
Reaction pathway
(c)
Use the graph to explain why this reaction is exothermic.
[1]
........................................................................................................................................
........................................................................................................................................
8
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 75
8.
Ammonia is an important compound used by industry and agriculture.
(a)
(i)
Describe, in terms of outer shell electrons, the bonding in a molecule
of ammonia.
You should include a suitable diagram showing outer shell electrons in
your answer.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
(ii)
Explain why ammonia is a gas at room temperature.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
(b)
The diagram and equation below outline the manufacture of ammonia by the
Haber process.
ammonia
H2
The forward reaction is exothermic
(i)
Using atmospheric pressure would be safer and cheaper. Explain the
effect of using atmospheric pressure in the process.
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 76
(ii)
Increasing the temperature would increase the rate of reaction. Explain
why a catalyst is used to increase the rate rather than using a higher
temperature.
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
(c)
The diagram below shows the stages in the industrial production of nitric acid.
Stage 1
nitric acid
solution
Stage 2
Stage 3
molten ammonium
nitrate is sprayed
into a cooling
chamber
ammonia
solution
ammonium
nitrate pellets
ammonium nitrate
solution formed
neutral solution is heated leaving
molten ammonium nitrate
air is blown in
to cool
chamber
(i)
Write a balanced symbol equation for the reaction occurring in stage 1.
[2]
.............................................................................................................................
(ii)
The industrial process can be adapted and carried out using simple
laboratory apparatus.
Describe and explain the laboratory method for obtaining a
sample of ammonium nitrate from 1.0 M solutions of nitric acid
and ammonia.
[3]
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 77
(d)
Ammonium phosphate, (NH4)3PO4 is used as a fertiliser.
(i)
Calculate the percentage (%) of nitrogen in ammonium phosphate to
one decimal place.
[2]
Ar(H) = 1
Ar(N) = 14 Ar(O) = 16 Ar(P) = 31
% of nitrogen = ………..%
(ii)
Fertilisers often contain more than one compound. Suggest how you
could carry out a test to distinguish between the two fertilisers below.
Both fertiliser A and B are in pellet form and contain compounds which
are all water soluble.
Practical details are not required.
[3]
Fertiliser
Composition
Fertiliser A
Mixture of ammonium nitrate,
ammonium nitrate, potassium nitrate,
magnesium sulfate
Fertiliser B
Mixture of ammonium nitrate,
potassium nitrate
…………………………………………………………………………………………..
…………………………………………………………………………………………..
…………………………………………………………………………………………..
20
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 78
9.
An investigation was carried out to find out which alcohol gives out the most energy
when burned.
The diagram below shows the apparatus used.
In each case sufficient alcohol was burned to increase the temperature of 100 g of
water by 40 °C.
Each alcohol was tested three times and the mean mass required was calculated.
The results are shown in the table below.
Alcohol
ethanol
propanol
butanol
(a)
Total mass
before (g)
Total mass
after (g)
Mass of
alcohol
required (g)
184.29
182.79
1.50
182.79
181.26
1.53
181.20
179.83
1.48
198.21
196.99
1.22
196.86
195.67
1.19
195.57
194.43
1.26
177.05
175.59
1.46
175.26
174.20
1.06
174.94
174.03
0.90
Mean mass
of alcohol
required (g)
Energy
released
(kJ/ g)
1.50
11.2
1.22
13.8
0.98
The energy in Joules (J) released by each alcohol can be calculated using the
formula:
energy released 
mass of water  4.2  temperature change
mean mass of alcohol required
Use this formula to calculate the energy released in kJ / g when 0.98 g of
butanol is burned.
Give your answer to three significant figures.
[2]
energy released = ………………….. kJ / g
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 79
(b)
One of the mass values for butanol was not used in calculating the mean
mass required.
Identify this value and suggest one experimental error that would explain why
this result was recorded.
[2]
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
(c)
The theoretical values for the energy released by each alcohol are given in the
table below.
Alcohol
Theoretical values for energy released (kJ/g)
ethanol
29.7
propanol
33.6
butanol
36.1
Compare the experimental and the theoretical values and give two
conclusions that can be drawn from the results of the investigation.
[2]
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
(d)
Describe and explain two improvements that could be made to the method to
obtain experimental values closer to the theoretical values of energy released.
[4]
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
10
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 80
10.
(a)
A food scientist was asked to check the quality of a bottle of vinegar. Vinegar
contains ethanoic acid, CH3COOH.
The apparatus shown was used to find the concentration of ethanoic acid in
vinegar.
Dilute sodium hydroxide of concentration 0.90 mol/dm3 was added a little at a
time to 25.0 cm3 of vinegar until the indicator changed colour. The procedure
was carried out three times.
Volume of sodium
3
hydroxide added (cm )
(i)
Run 1
Run 2
Run 3
24.1
23.9
24.0
Ethanoic acid reacts with sodium hydroxide solution according to the
equation below.
CH3COOH
I
+
NaOH
CH3COONa
+
H2O
Calculate the mean volume of sodium hydroxide needed to
neutralise 25.0 cm3 of vinegar.
[1]
mean volume = ........................... cm3
II
Using the mean volume of sodium hydroxide, calculate the
concentration of the ethanoic acid in mol/dm3.
[3]
concentration = ........................... mol / dm3
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 81
(ii)
The label on the vinegar bottle states that it contains a minimum of 5 g
of ethanoic acid, CH3COOH, in 100 cm3 vinegar.
I
Calculate the relative molecular mass, Mr, of ethanoic acid.
[1]
Mr = .........................
II
Show whether the information on the label is correct.
[2]
.................................................................................................................
.................................................................................................................
(b)
Jo measured the pH of two different acids in his laboratory. He knew the
concentration of the hydrochloric acid. His results and conclusion are below.
Acid
pH
0.10 mol / dm3 hydrochloric
acid
1
ethanoic acid
3
Jo’s conclusion stated:
‘that since the pH difference is 2 then the concentration of the hydrochloric
acid must be 100 (10x10) times great than the ethanoic acid. Since the
hydrochloric acid concentration is 0.10 mol/dm3 then the ethanoic acid
concentration must be 0.0010 mol /dm3.
Explain whether Jo has correctly interpreted the information.
[4]
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
11
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 82
11.
Explain the differences between addition polymerisation and condensation
polymerisation.
Include relevant equations in your answer.
[6 QER]
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
6
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 83
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 84
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 85
COMPONENT 1 - Concepts in Chemistry
HIGHER TIER
MARK SCHEME
GENERAL INSTRUCTIONS
Recording of marks
Examiners must mark in red ink.
One tick must equate to one mark (apart from the questions where a level of response mark scheme is applied).
Question totals should be written in the box at the end of the question.
Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.
Marking rules
All work should be seen to have been marked.
Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.
Crossed out responses not replaced should be marked.
Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 86
Extended response question
A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly,
decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality
of the response. Then decide which mark to award within the level. Award the higher mark in the level if there is a good match with both the
content statements and the communication statements.
Marking abbreviations
The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded.
cao
ecf
bod
=
=
=
© WJEC CBAC Ltd.
correct answer only
error carried forward
benefit of doubt
GCSE CHEMISTRY Sample Assessment Materials 87
Question
1
Marking details
AO1
AO2
Marks available
AO3
Total
Maths
5
5
1
1
1
1
(a)
10 (1)
40
Ca (1)
20
(b)
18 (1)
9 (1)
20 (1)
(i)
(ii)
© WJEC CBAC Ltd.
Prac
GCSE CHEMISTRY Sample Assessment Materials 88
Question
(c)
(i)
(ii)
© WJEC CBAC Ltd.
Marking details
Atomic weights (1)
Patterns of reactivity (1)
I
AO1
AO2
Marks available
AO3
Total Maths
2
2
K and Cu occupy their own spaces – have different properties (1)
Gaps filled – new elements discovered (1)
Additional group – noble gases discovered (1)
Transition metals placed together – have similar properties (1)
3
3
Question 1 total
5
Prac
Any three of the following
Must have explanation as well as observation
7
0
12
0
0
GCSE CHEMISTRY Sample Assessment Materials 89
Question
2
(a)
(i)
(ii)
(b)
© WJEC CBAC Ltd.
(i)
(ii)
Marking details
AO1
Scales: Both axes
(1)
Plotting: All correct
(2)
Any 8 correct (1)
Line:
Smooth curve through all points (1)
Judgement by eye
Graph rises as acid and alkali react / exothermic reaction (1)
Peak / no further increase – point at which neutralisation is
complete / alkali used up (1)
Graph falls – cooling to room temperature as no further
reaction takes place / cool acid continues to be added (1)
AO2
4
Marks available
AO3
Total
Maths
4
4
3
pH / universal indicator
Colour change as acid added (1)
Description of colour change (1)
e.g. purple to green to red
1
2
Question 2 total
3
4
3
Prac
3
3
1
2
1
2
10
4
6
GCSE CHEMISTRY Sample Assessment Materials 90
Question
3
(a)
(i)
(ii)
(b)
(c)
Marking details
11.1 (2)
AO1
4/36 x 100
Award (1) for 4/36 Allow ecf
Low atom economy (1)
Not efficient process/
Not economic process/
Not a ‘green’ process /
O2 is a waste product …any one for (1)
Straight line from (0,0) of lower gradient (1)
Line to 0.2 g after 10 minutes) (1)
Raw material is water …renewable natural resource (1)
AO2
1
1
Marks available
AO3
Total
Maths
2
2
Prac
2
2
2
2
2
2
2
4
8
4
2
2
Combustion product is water ….does not contribute to global
warming (1)
Question 3 total
© WJEC CBAC Ltd.
0
4
GCSE CHEMISTRY Sample Assessment Materials 91
Marking details
Question
4
(a)
(b)
(c)
AO1
Increase in demand for copper for relevant use with brief
explanation e.g. more copper wire required as more electrical
appliances built, more copper for pipes as central heating
installed in more homes
(i)
(ii)
(iii)
(iv)
Any two of the following
High grade copper ore reserves being used up (1)
Lower supply leads to increasing costs (1)
Negative effect on landscape / habitat (1)
Plants absorb copper compounds through their roots
copper(II) oxide
Any two disadvantages for (1) –explanation (1)
e.g. Large scale harvesting of plants – more expensive than
mining
Small amounts of copper per plant – huge numbers of plants
needed
Huge areas for plant growth – competition with food crops
Supply limited by plant growth cycle – poor crop because of
drought
1
2
1
1
3
3
1
Iron is a more reactive metal than copper (1)
1
Iron displaces copper / iron reduces copper(II) ions (1)
1
CuSO4 + Fe → FeSO4 + Cu (1)
© WJEC CBAC Ltd.
Maths
Prac
1
2
1
1
Add iron to copper(II) sulfate (1)
Question 4 total
AO2
Marks Available
AO3
Total
4
3
1
10
2
0
12
0
3
GCSE CHEMISTRY Sample Assessment Materials 92
Question
5
(a)
Marking details
AO1
AO2
Marks Available
AO3
Total
Maths
Al3+ (1)
(i)
4e (1)
(ii)
2
2
4
4
Up to two methods for one mark each with second mark available
for development of point, e.g.
Cryolite added to lower melting point of aluminium oxide (1)
Process can operate at a lower temperature (1)
Cheaper source of electricity (1)
Locate in countries with plentiful energy / fossil fuel reserves or
nuclear power (1)
(iii)
I
Mr Al2O3 = 102 (1)
Mass ratio 204 : 108 (1)
Answer = 1080 (1)
Accept calculation by alternative method using mole ratios
© WJEC CBAC Ltd.
3
3
3
Prac
GCSE CHEMISTRY Sample Assessment Materials 93
Question
Marking details
II
(b)
AO2
Maths
Prac
Mass ratio 2040 : 960 (1)
Number of moles oxygen = 960 × 106
32
(1)
Volume = 3 × 107 × 0.024 = 7.2 × 105
(1)
(i)
mobile sea of electrons
(ii)
layers of atoms/ions slide over one another
Question 5 total
© WJEC CBAC Ltd.
AO1
Marks Available
AO3
Total
3
3
1
1
1
1
8
6
0
14
3
6
0
GCSE CHEMISTRY Sample Assessment Materials 94
Question
6
(a)
(b)
(i)
(i)
Marking details
A
sodium iodide (1)
B
ammonium carbonate (1)
C
calcium chloride (1)
D
iron(II) bromide (1)
Cu2+(aq) + 2OH‒(aq) → Cu(OH)2(s)
AO1
AO2
2
(2)
Marks Available
AO3
Total Maths
2
4
2
2
3
3
Prac
4
Must include correct state symbols for full marks to be awarded
If equation not correct award (1) for
correct ions LHS and compound RHS
correct balancing
(ii)
FeBr3 + 3NaOH → Fe(OH)3 + 3NaBr (3)
Ignore state symbols
If equation not correct award (1) for each of the following
Fe(OH)3 on product side
NaBr on product side
Question 6 total
© WJEC CBAC Ltd.
2
5
2
9
0
4
GCSE CHEMISTRY Sample Assessment Materials 95
Question
7
(a)
Marking details
Energy released in forming bonds = (4 × 523) + (4 × 463) (1)
3944 (1)
AO1
1
AO2
Maths
Prac
1
Total energy needed to break bonds = 3944 ‒ 1103 = 2841 (1)
2841 = (4 × 339) + (3 × O=O) (1)
(O=O) = 495 (1)
Marks Available
AO3
Total
1
1
1
5
2
2
5
Error carried forward (ecf) possible
(b)
(1) for each of A and B as shown
A
B
(c)
© WJEC CBAC Ltd.
Products have less energy than the reactants
1
Question 7 total
3
1
4
1
8
5
0
GCSE CHEMISTRY Sample Assessment Materials 96
Question
8
(a)
(i)
Marking details
AO1
Nitrogen atom shares electrons with three hydrogen atoms
H
N
AO2
1
Marks Available
AO3
Total Maths
H
1
2
H
(ii)
(b)
(i)
Weak forces between ammonia molecules (1)
Molecules have sufficient energy at room temperature to
Overcome these forces
Equilibrium position moves to oppose any change (1)
2
2
1
Decreasing pressure moves equilibrium position towards the side
with more gas molecules in order to oppose change (1)
Left hand side has more gas molecules therefore yield of ammonia
decreases (1)
(ii)
2
3
Increasing temperature moves equilibrium position in the
endothermic direction (1)
This is the right to left reaction therefore yield of ammonia
decreases (1)
A catalyst increases rate without affecting the yield (1)
© WJEC CBAC Ltd.
3
3
Prac
GCSE CHEMISTRY Sample Assessment Materials 97
(c)
(i)
HNO3 + NH3 → NH4NO3 (2)
2
2
If equation not correct award (1) for correct reactants or correct
products
Accept alternative equation
HNO3 + NH4OH → NH4NO3 + H2O (2)
(ii)
(d)
(i)
(ii)
© WJEC CBAC Ltd.
React equal volumes of HNO3 and NH3 to get neutral solution (1)
1
Heat/boil solution to remove/evaporate some of the water (1)
1
Leave to cool and crystallise (1)
1
Mr (NH4)3PO4 = 149 (1)
42/149 x100 = 28.2 (1)
Award 42/149 (1) if answer is incorrect
Dissolve pellets in water / add pellets to water to make solution
Add dilute barium chloride solution to each solution
Fertiliser A – no change observed, fertiliser B white precipitate (of
barium sulfate / barium sulfate & barium phosphate) (1)
2
Question 8 total
10
3
2
2
1
3
10
0
20
3
2
3
2
6
GCSE CHEMISTRY Sample Assessment Materials 98
Question
9
(a)
(b)
Marking details
AO1
17143 (1)
Accept anything up to full calculator reading
17.1 (1)
Must be given to 3 significant figures
First reading / 1.46 (1)
AO2
1
Marks Available
AO3
Total Maths
Prac
2
2
1
Any of the following for (1)
Heat loss here was greater than for other measurements e.g.
bigger gap between flame and beaker
More than 100 g of water measured into beaker
2
2
2
2
2
2
2
4
4
4
8
10
Credit other sensible suggestions
(c)
Experimental values much lower than / around half the
theoretical values (1)
Same trend in results i.e. amount of energy released increases
from ethanol to propanol to butanol (1)
(d)
Answers based on any two of the following
Enclose apparatus / reduce drafts (1)
Less heat lost between flame and beaker (1)
Copper can instead of glass beaker / better conductor (1)
More heat transferred to water (1)
Improve insulation / lag beaker / lid on beaker (1)
Less heat lost after transfer to water (1)
Credit other sensible improvement (1) and explanation (1)
Question 9 total
© WJEC CBAC Ltd.
1
1
2
10
GCSE CHEMISTRY Sample Assessment Materials 99
Question
10
(a)
(i)
Marking details
I
24.0 ‒ do not accept 24
II
Moles NaOH = 0.0216
AO1
1
AO2
Marks Available
AO3
Total
1
Maths
Prac
1
3
3
2
2
(1)
1 mol NaOH : 1 mol CH3COOH
Concn CH3COOH = 0.864
(1)
(1)
3
3
Award full marks for correct answer with no working
Error carried forward possible (ecf)
(ii)
I
60
II
Moles CH3COOH in 100 cm3 vinegar = 0.0833 (1)
1
1
Conc CH3COOH is 0.833 therefore label information
is correct (1)
(b)
Jo is incorrect to say that the concentration of the ethanoic acid
is 0.0010 mol/dm3. – Marks given for logical reasoning:
pH is a measure of conc of H+ ions in solution (1)
There is a difference of 100x in H+ concentration because the
pH changes 10 times with each pH unit/ Two unit changes in pH
means a 10 x 10 =100 change in H+ conc (1)
But ethanoic acid is a weak acid and does not completely ionise
(1)
so concentration of the acid is not same as/ is higher than the
H+ ion conc (1)
Question 10 total
© WJEC CBAC Ltd.
2
2
1
2
3
4
4
6
11
6
6
GCSE CHEMISTRY Sample Assessment Materials 100
Question
11
Marking details
Indicative content:
AO1 allocation - Addition polymers e.g. polyethene, polychloroethene
etc.
One type of monomer, unsaturated therefore reactive, C=C double
bond opens, monomers join to form saturated polymer chain
Condensation polymers e.g. nylon
May have one or two different monomers, must have reactive
functional groups at both ends, functional groups react to produce
polymer chain, small molecule produced at each bond new bond
location
AO2 allocation - Representation of reactions using appropriate
equations/block diagrams
AO1
AO2
4
2
4
2
Marks Available
AO3
Total
Maths
Prac
0
0
6
5 ─ 6 marks: Comparison of monomer type/number, functional groups
and reaction products; illustrated with reference to one named
example for both and good attempt at one equation.
There is a sustained line of reasoning which is coherent, substantiated
and logically structured. The information included in the response is
relevant to the argument.
3 ─ 4 marks: Comparison of at least one of monomer type/number,
functional groups and reaction products; one named example for both
There is a line of reasoning which is partially coherent, supported by
some evidence and with some structure. Mainly relevant information is
included in the response but there may be some minor errors or the
inclusion of some information not relevant to the argument.
1 ─ 2 marks: Description of at least one characteristic of any
monomer linked to the correct type of polymerisation.
There is a basic line of reasoning which is not coherent, supported by
limited evidence and with very little structure. There may be significant
errors or the inclusion of information not relevant to the argument.
0 marks: No attempt made or no response worthy of credit.
Question 11 total
© WJEC CBAC Ltd.
0
6
GCSE CHEMISTRY Sample Assessment Materials 101
COMPONENT 1 - Concepts in Chemistry
HIGHER TIER
SUMMARY OF MARKS ALLOCATED TO ASSESSMENT OBJECTIVES
Question
AO1
AO2
AO3
TOTAL MARK
MATHS
PRAC
1
5
7
0
12
0
0
2
3
4
3
10
4
6
3
0
4
4
8
4
2
4
10
2
0
12
0
3
5
6
8
0
14
6
0
6
2
5
2
9
0
4
7
3
4
1
8
5
0
8
10
10
0
20
2
6
9
1
1
8
10
2
10
10
2
3
6
11
6
6
11
4
2
0
6
0
0
TOTAL
48
49
24
120
29
37
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 103
Candidate Name
Centre Number
Candidate Number
GCSE CHEMISTRY
COMPONENT 2
Applications in Chemistry
FOUNDATION TIER
SAMPLE PAPER
(1 hour 15 minutes)
For Examiner’s use only
Section A
Section B
Question Maximum
Mark
1
5
2
11
3
6
4
6
5
7
6
4
7
6
8
15
Total
60
Mark
Awarded
ADDITIONAL MATERIALS
In addition to this examination paper you will need a resource booklet, a calculator and a
ruler.
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen. Do not use correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet.
INFORMATION FOR CANDIDATES
This paper is in two Sections, Section A and Section B.
Section A: 45 marks. Answer all questions. You are advised to spend about 50 minutes on
this section.
Section B: 15 marks. Read the article in the resource booklet carefully then answer all
questions. You are advised to spend about 25 minutes on this section.
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 7.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 104
SECTION A
Answer all questions.
1
(a)
Draw lines to match each diagram below with the correct name of the
apparatus. One has been done for you.
•
•
•
•
•
© WJEC CBAC Ltd.
[2]
balance
Bunsen burner
burette
pipette
measuring cylinder
GCSE CHEMISTRY Sample Assessment Materials 105
(b)
Choose a method from the box to answer parts (i) to (iii).
chromatography
distillation
electrolysis
filtration
Name the method you would use to separate:
(i)
two liquids (water and ethanol)
……………………………
[1]
(ii)
the colourings in a food dye
..…………………………..
[1]
(iii)
a precipitate from water
……………………………
[1]
5
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 106
2.
(a)
The following table shows the colours of universal indicator at different pH
values.
colour
red
orange
yellow
green
blue
navy blue
purple
pH
0-2
3-4
5-6
7
8-9
10-12
13-14
Use this information to help you complete the table below.
(b)
Substance
Colour with
universal indicator
detergent
purple
pH value
distilled water
7
soap
8
[3]
Acid, alkali or
neutral?
Different lengths of magnesium ribbon were put into separate beakers each
containing 25 cm3 dilute hydrochloric acid and the temperature measured.
The initial temperature of the acid in each beaker was 16 oC.
The results are shown in the table below. Two temperatures are missing.
Length of magnesium
ribbon (cm)
Final temperature
(oC)
Initial temperature
(oC)
Temperature rise
(OC)
(i)
2
4
6
8
10
12
20
23
28
33
35
……….
16
16
16
16
16
16
4
7
12
17
19
……….
Complete the table by using the thermometer reading shown below. [2]
Thermometer reading when
12 cm of magnesium was used.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 107
(ii)
Plot the length of magnesium ribbon against the temperature rise and
draw a suitable line.
[3]
30
25
20
Temperature rise 15
(oC)
10
5
0
0
2
4
6
8
10
12
14
Length of magnesium ribbon (cm)
(iii)
Use your graph to find the temperature rise if 5 cm of magnesium was
added to 25 cm3 dilute hydrochloric acid.
[1]
temperature rise …………. oC
(iv)
Put a tick (√) next to the statement which describes the temperature
rise you would expect if the hydrochloric acid was replaced with
vinegar. Give a reason for your choice.
[2]
temperature rise will be higher with vinegar than with
hydrochloric acid
temperature rise will be lower with vinegar than with
hydrochloric acid
temperature rise will be the same with vinegar as with
hydrochloric acid
Reason for choice
…………………………………………………………………………………
11
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 108
3.
The diagrams below show the stages in making the compound zinc sulphate by
reacting zinc carbonate with dilute sulfuric acid. The diagram showing the apparatus
for Stage 2 is missing.
Stage 2
Stage 1
Stage 3
colourless
solution
sulphuric
acid
Excess zinc carbonate is
added to dilute sulfuric acid,
the mixture being
continuously stirred
(a)
Excess zinc carbonate
is removed
Colourless solution is left in an
evaporating basin at room
temperature to obtain white
crystals of copper sulfate
State what you would see when excess zinc carbonate is added.
[1]
………………………………………………………………………………………………….
(b)
State why excess zinc carbonate is added.
[1]
…………………………………………………………………………………………………..
(c)
Draw the apparatus you would use to carry out stage 2.
Label the excess zinc carbonate on your diagram.
(d)
Put a tick (√) next to the box that shows the estimated time it would take for
all the water to evaporate from 25 cm3 of zinc sulfate solution in stage 3. [1]
3 hours
3 days
3 weeks
[3]
3 years
6
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 109
4.
Hydrogen peroxide solution decomposes very slowly at room temperature.
H2O2(aq)
+
2H2O(l)
O2(g)
This reaction can be catalysed using manganese(IV) oxide.
The statement below shows the definition of a catalyst.
“A catalyst will change the speed of a chemical reaction but will not be used up
during the reaction.”
A student carried out an investigation to find out if it is true that a catalyst is not used
up in a reaction.
1.50 g of manganese(IV) oxide powder was accurately weighed and put into 20 cm3
of hydrogen peroxide solution. After the reaction has stopped, the reaction mixture
was filtered into a pre-weighed filter paper. The filtered manganese(IV) oxide and
filter paper was dried in an oven.
The mass readings are shown below.
Mass (g)
(a)
filter paper
1.26
manganese(IV) oxide and filter
paper after drying
2.74
recovered manganese(IV) oxide
1.48
Calculate the percentage (%) mass of manganese(IV) oxide recovered to one
decimal place.
[3]
% mass of manganese(IV) oxide recovered = ……….. %
(b)
Do you agree with the statement that ‘a catalyst is not used up in a reaction’
Give the reason for your decision.
[1]
…………………………………………………………………………………………………..
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 110
(c)
Suggest why not all of the manganese(IV) oxide was recovered and how this
problem could be overcome.
[2]
………….……………………………………………………………………………………….
………….……………………………………………………………………………………….
………….……………………………………………………………………………………….
6
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 111
5.
(a)
A compound was dissolved in water and tested as described below.
Use the information to complete the table and name the compound.
Solution of unknown
compound
dilute hydrochloric acid was
added, the gas produced
was passed through
limewater
a flame test was carried out.
[3]
Observation
Conclusion
limewater turned
milky
…………………………………………
…………………………………………
….…….………………………………
an orange flame
…………………………………………
………..……………………….………
…..…………………………………….
The compound is
(b)
…………………………………………………………..………
It is thought that magnesium ions have contaminated a solution containing
barium ions.
Use the information below to develop a method that will allow you to remove
barium ions and then test for the presence of magnesium ions.
[4]
Compound
sulfuric acid
Soluble or insoluble?
soluble
barium sulfate
insoluble
barium carbonate
insoluble
magnesium sulfate
magnesium carbonate
soluble
insoluble
sodium sulfate
soluble
sodium carbonate
soluble
Method to remove barium ions
……………………………………………………….…………………………………
………………………………………………………………………………………….
Test for magnesium ions
……………………………………………………….…………………………………
…………………………………………………………………………………………
7
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 112
6.
A student measured out 25 cm3 of a sodium carbonate solution. The sodium carbonate
solution had a concentration of 1.06 g / dm3.
Calculate the mass of sodium carbonate (Na2CO3) that was in 25 cm3 of this solution.
Give your answer in units of g and mg.
[4]
……………………………………………………………………………………………….
……………………………………………………………………………………………….
4
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 113
7.
Describe and explain an investigation you would carry out to find the relative
positions of copper, iron and magnesium in the reactivity series. Include equations
where appropriate.
You are provided with:
- solid samples of copper, iron and magnesium
- solid samples of copper(II) sulfate, iron(II) sulfate and magnesium sulfate.
[6 QER]
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
6
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 114
SECTION B
Read the article in the resource booklet and answer all the questions that follow.
8.
(a)
Describe the bonding between carbon atoms in diamond.
Include a dot and cross diagram in your answer.
Details of the structure of diamond are not required.
[3]
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(b)
(i)
Explain why graphene is a good conductor of electricity.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
(ii)
Explain why graphite is soft and slippery and can act as a lubricant. [2]
…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
(iii)
Diamond is a very dense allotrope of carbon because the carbon
atoms are tightly packed. Calculate the volume of the cube containing
carbon atoms in Diagram 2. Give the unit.
[1]
volume = …………..
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 115
(c)
Determine the molecular formula of the fullerene identified using mass
spectroscopy in the article.
Show your working.
[2]
molecular formula = ………….
(d)
(i)
Calculate the specific strength of Kevlar (Table 1) and use this value
to estimate the breaking length.
[3]
specific strength
………… kN m/kg
breaking length …………… km
(ii)
Explain why carbon nanotubes may eventually replace materials like
steel and aluminium in the manufacture of power lines.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
15
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 116
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 117
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 119
GCSE CHEMISTRY
COMPONENT 2
Applications in Chemistry
FOUNDATION TIER
RESOURCE BOOKLET
for use in Section B
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 120
Allotropes of carbon
Carbon exists as a number of different allotropes. Some important allotropes of carbon are
described in this article.
Diagram 1 Diamond and graphite
Diamond
Graphite
The structure of diamond can be related to a cube. The diagram below shows this.
Diagram 2 A unit cubic cell of diamond
c
b
a
The cell dimension a = b = c = 0.36 nm
Diagram 3 Graphene and fullerene
Graphene
© WJEC CBAC Ltd.
Fullerene
GCSE CHEMISTRY Sample Assessment Materials 121
Graphene and fullerenes
Graphene is a single sheet with the carbon atoms arranged in the layer as they are in
graphite.
Fullerenes are cage-like spherical molecules. They were first discovered using a method
known as mass spectroscopy. One fullerene identified by mass spectrometry had a relative
molecular mass of 720.
Carbon nanotubes
Carbon nanotubes are made of graphene sheets rolled into the shape of a cylinder, often
with at least one end closed.
Diagram 4 Carbon nanotube
Properties of carbon nanotubes
The specific strength is a material's tensile strength divided by its density. It is also known
as the strength-to-weight ratio.
Another way to describe specific strength is breaking length which is the maximum length
of a vertical column of the material that could support its own weight when suspended only
at the top.
Table 1
Tensile strength
(MPa)
Density
(g/cm³)
Specific
strength
(kN m/kg)
Breaking length
(km)
stainless steel
505
8.00
63.1
6.4
aluminium
572
2.81
204
20.8
kevlar
3 620
1.44
carbon
nanotube
62 000
1.34
46 268
4 716
Material
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 122
COMPONENT 2 - Applications in Chemistry
FOUNDATION TIER
MARK SCHEME
GENERAL INSTRUCTIONS
Recording of marks
Examiners must mark in red ink.
One tick must equate to one mark (apart from the questions where a level of response mark scheme is applied).
Question totals should be written in the box at the end of the question.
Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.
Marking rules
All work should be seen to have been marked.
Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.
Crossed out responses not replaced should be marked.
Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 123
Extended response question
A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly,
decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality of the
response. Then decide which mark to award within the level. Award the higher mark in the level if there is a good match with both the
content statements and the communication statements.
Marking abbreviations
The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded.
cao
ecf
bod
=
=
=
© WJEC CBAC Ltd.
correct answer only
error carried forward
benefit of doubt
GCSE CHEMISTRY Sample Assessment Materials 124
Question
1
(a)
(b)
Marking details
AO1
AO2
Marks Available
AO3
Total
All connected correctly (2)
Any two lines drawn correctly (1)
2
2
(i)
Distillation
1
1
(ii)
Chromatography
1
1
(iii)
Filtration
1
1
Question 1 total
5
© WJEC CBAC Ltd.
0
0
5
Maths
Prac
0
5
GCSE CHEMISTRY Sample Assessment Materials 125
Question
2
(a)
(b)
(i)
(ii)
Marking details
Detergent
13/14
alkali
Distilled water green
neutral
Soap
blue
alkali
final temperature 45 [1]
temperature rise 26 [1]
both needed for [1]
both needed for [1]
both needed for [1]
AO1
1
Plotting - All correct [2] any five correct [1] ± 0.02
Allow e.c.f for point 12 cm
AO2
2
Marks Available
AO3
Total
3
Maths
2
2
3
3
3
1
Prac
3
2
Line - straight line of best fit ( ruler) Judgement by eye
Allow - e.c.f. for point 12 cm
(iii)
10.5 ± 1 e.c.f.
1
1
(iv)
Temperature rises are lower √ (1)
1
2
Weaker acid / lower pH
Question 2 total
© WJEC CBAC Ltd.
(1) Do not accept ‘less concentrated’
1
2
9
0
11
4
5
GCSE CHEMISTRY Sample Assessment Materials 126
Question
3
Marking details
(a)
solid (left at bottom of beaker /
zinc carbonate left at bottom of beaker)
(b)
to neutralise all the acid /
to cancel out all the acid
AO1
1
AO2
Marks available
AO3
Total
1
1
1
3
3
Maths
Prac
1
1
(c)
(filter paper) (1)
excess zinc
carbonate [1]
(d)
(filter funnel) (1)
2 days √
Question 3 total
© WJEC CBAC Ltd.
3
1
5
1
1
0
6
1
0
6
GCSE CHEMISTRY Sample Assessment Materials 127
Question
4
(a)
Marking details
AO1
98.7 (3)
If answer is incorrect award
AO2
3
Marks available
AO3
Total
3
Maths
3
Prac
1.48/1.5 x 100 (1)
98.66 (1)
(b)
Yes - any sensible decision
e.g. ‘only 1.3 out’/ ’difference due to procedural errors’ /
‘poor experimental method’
Accept ‘no’ with sensible decision e.g. ‘1.3 out’
1
1
1
(c)
not all manganese oxide recovered during filtering(1)……
…..wash beaker out with water ( to retrieve all manganese
oxide) (1)
2
2
2
3
6
Question 4 total
© WJEC CBAC Ltd.
0
3
3
3
GCSE CHEMISTRY Sample Assessment Materials 128
Question
5
(a)
Marking details
carbonate present/
CO32-
AO1
AO2
present (1)
sodium present / Na+ present (1)
(b)
Marks available
AO3
Total
1
3
1
sodium carbonate (allow ecf ) (1)
1
Remove barium: Add solution of sodium carbonate (1)
Filter off precipitate of barium carbonate (1)
1
1
Test for magnesium ions by adding sodium carbonate solution
(1)
1
Maths
Prac
3
4
4
1
White precipitate if Mg2+ present (1)
Question 5 total
© WJEC CBAC Ltd.
1
0
6
7
0
7
GCSE CHEMISTRY Sample Assessment Materials 129
Question
6
Marking details
mass = 1.06 x 25/1000 (1)
=0.0265 g and 26.5 mg (accept ecf for answer in mg)
Must give units in both cases for 2 marks.
No units in either or both cases then only 1 mark for each
correct numerical answer
Question 6 total
© WJEC CBAC Ltd.
AO1
1
AO2
Marks available
AO3
Total
3
1
3
0
Maths
Prac
4
2
4
4
2
4
GCSE CHEMISTRY Sample Assessment Materials 130
Question
7
Marking details
Indicative content:
AO1 allocation Description of method:
dissolve salts in water
add each metal to solution of other two aqueous metal
solutions
Expected observations
copper to solutions of iron & magnesium salts no change
iron and copper II sulfate – solution turns colourless,
coppery coloured deposit. No change with Mg salt
magnesium to iron(II) and copper salts. Solutions turn
colourless. Coppery coloured deposit with copper(II)
solution
AO2 allocation Explanation
in terms of displacement reactions; order metals in
reactivity series
relevant equations
5 ─ 6 marks:
Explanation of displacement, correct observations;
correct conclusion; three relevant equations
There is a sustained line of reasoning which is coherent,
substantiated and logically structured. The information included
in the response is relevant to the argument
3 ─ 4 marks:
All reactions to be done given; some outcomes correct;
conclusion given
There is a line of reasoning which is partially coherent,
supported by some evidence and with some structure.
Mainly relevant information is included in the response but there
may be some minor errors or the inclusion of some information
not relevant to the argument.
© WJEC CBAC Ltd.
AO1
AO2
Marks available
AO3
Total
6
4
2
Maths
Prac
6
GCSE CHEMISTRY Sample Assessment Materials 131
1 ─ 2 marks:
Some reactions to be done given; few outcomes correct;
conclusion attempted
There is a basic line of reasoning which is not coherent,
supported by limited evidence and with very little structure.
There may be significant errors or the inclusion of information
not relevant to the argument.
0 marks: No attempt made or no response worthy of credit.
Question 7 total
© WJEC CBAC Ltd.
4
2
0
6
0
6
GCSE CHEMISTRY Sample Assessment Materials 132
Question
8
(a)
Marking details
Covalent bonding (1)
Each carbon atom shares electron pairs with four other carbon
atoms (1)
AO1
1
AO2
Marks available
AO3
Total
3
Maths
1
C
C
C
1
C
C
(b)
(i)
(1)
Three valence electrons of carbon are used up in forming the
covalent bonds (1)
The fourth electron is delocalised and able to move (1)
(ii)
In graphite, the carbon atoms are arranged in flat parallel layers
attracted to adjacent layers by weak forces (1)
This allows each layer to slide over the other easily (1)
(iii)
0.047 nm3
© WJEC CBAC Ltd.
Both answer and unit required
2
2
2
2
1
1
1
Prac
GCSE CHEMISTRY Sample Assessment Materials 133
Question
(c)
(d)
Marking details
AO1
Number carbon atoms = 720/12 (1)
Molecular formula C60 (1) (allow error carried forward)
(i)
(ii)
© WJEC CBAC Ltd.
Marks available
AO3
Total
1
3 620/1.44 (1)
= 2 514 (1)
Estimate of approx. 251/252 (also allow error carried forward accept value if it is clearly 10:1 ratio of specific strength)
Carbon nanotubes have a much higher strength-to-weight ratio
(1)
So will be stronger and lighter (1)
Question 8 total
AO2
1
3
6
6
Maths
Prac
2
3
2
2
3
15
3
4
0
GCSE CHEMISTRY Sample Assessment Materials 134
COMPONENT 2 - Applications in Chemistry
FOUNDATION TIER
SUMMARY OF MARKS ALLOCATED TO ASSESSMENT OBJECTIVES
Question
AO1
AO2
AO3
TOTAL MARK
MATHS
PRAC
1
5
0
0
5
0
5
2
2
9
0
11
4
5
3
5
1
0
6
0
6
4
0
3
3
6
3
3
5
1
0
6
7
0
7
6
1
3
0
4
2
4
7
4
2
0
6
0
6
8
6
6
3
15
4
0
TOTAL
24
24
12
60
13
36
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 135
Candidate Name
Centre Number
Candidate Number
GCSE CHEMISTRY
COMPONENT 2
Applications in Chemistry
HIGHER TIER
SAMPLE PAPER
(1 hour 15 minutes)
For Examiner’s use only
Question
Section A
1
Maximum
Mark
15
Section B
2
7
3
8
4
7
5
7
6
10
7
6
Total
Mark Awarded
60
ADDITIONAL MATERIALS
In addition to this examination paper you will need a resource booklet, a calculator and a
ruler.
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen. Do not use correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet.
INFORMATION FOR CANDIDATES
This paper is in two sections, Section A and Section B.
Section A: 15 marks. Read the article in the resource booklet carefully then answer all
questions. You are advised to spend about 25 minutes on this section.
Section B: 45 marks. Answer all questions. You are advised to spend about 50 minutes on
this section.
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 7.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 136
SECTION A
Read the article in the resource booklet and answer all the questions that follow.
1.
(a)
Describe the bonding between carbon atoms in diamond.
Include a dot and cross diagram in your answer.
Details of the structure of diamond are not required.
[3]
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
(b)
(i)
Explain why graphene is a good conductor of electricity.
[2]
………………………………………………………………………………………..
………………………………………………………………………………………..
………………………………………………………………………………………..
(ii)
Explain why graphite is soft and slippery and can act as a lubricant. [2]
………………………………………………………………………………………..
………………………………………………………………………………………..
………………………………………………………………………………………..
(iii)
Diamond is a very dense allotrope of carbon because the carbon
atoms are tightly packed. Calculate the volume of the cube containing
carbon atoms in Diagram 2. Give the unit.
[1]
volume = …………..
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 137
(c)
Determine the molecular formula of the fullerene identified using mass
spectroscopy in the article.
Show your working.
[2]
molecular formula ………….
(d)
(i)
Calculate the specific strength of Kevlar (Table 1) and use this value
to estimate the breaking length.
[3]
specific strength
………… kN m/kg
breaking length
(ii)
…………… km
Explain why carbon nanotubes may eventually replace materials like
steel and aluminium in the manufacture of power lines.
[2]
………………………………………………………………………………………….
………………………………………………………………………………………….
………………………………………………………………………………………….
15
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 138
SECTION B
Answer all questions.
2.
The diagram shows the apparatus which can be used to separate a mixture of
ethanol and water. Ethanol has a boiling point of 78 °C.
distillate
(a)
Explain how the mixture is separated.
[4]
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(b)
Compound X has a boiling point of 75 °C.
(i)
Suggest why this method would not be very effective in separating
compound X and ethanol.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
(ii)
Suggest how you could adapt the method to improve the separation of
compound X and ethanol.
[1]
…………………………………………………………………………………………
7
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 139
3.
Three students individually investigated the mass of copper formed when four
different masses of zinc powder were added to 50 cm3 of copper(II) sulfate solution.
stirrer
copper(II) sulfate solution
zinc powder
copper powder
The equation for the reaction is:
Cu2+(aq) + Zn(s)
Cu(s) +
Zn2+(aq)
The results obtained are shown in the table.
Mass of copper formed (g)
Mass of zinc
added (g)
Student A
Student B
Student C
Mean
0.10
0.18
0.13
0.17
0.16
0.15
0.23
0.24
0.19
0.22
0.20
0.35
0.31
0.36
0.34
0.25
0.33
0.40
0.38
0.37
The graph on the next page shows the relationship between the mass of zinc added
and the expected mass of copper formed.
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GCSE CHEMISTRY Sample Assessment Materials 140
0.7
expected results
0.6
0.5
0.4
Mass of copper
formed (g)
0.3
0.2
0.1
0
0
(a)
0.05
0.1
0.15
0.2
Mass of zinc added (g)
0.25
0.3
Explain whether copper ions are oxidised or reduced in this reaction.
[1]
…………………………………………………………………………………………………..
(b)
(i)
Suggest a method to separate the copper powder from the solution. [1]
………………………………………………………………………………………..
(ii)
On the grid above, plot the mean mass of copper formed against the
mass of zinc added in this investigation. Draw a suitable line.
[3]
(iii)
Describe the main difference between the graph of expected results
and the one plotted using experimental results.
[1]
………………………………………………………………………………..
………………………………………………………………………………..
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GCSE CHEMISTRY Sample Assessment Materials 141
(iv)
Suggest two possible reasons for the difference between the graphs.
[2]
…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
….………………………………………………………………………………………
8
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 142
4.
Three groups of students used the apparatus shown in the diagram to investigate
how the electric current a sodium chloride solution produces depends on the
concentration of the solution.
The test was carried out using 50 cm3 of each solution. The students were given a
stock solution of concentration 0.5 M and asked to dilute this as required to make the
other solutions.
………………………
Table of results
Current (A)
Concentration (M)
Group A
Group B
Group C
0.1
0.07
0.06
0.06
0.2
0.14
0.12
0.13
0.3
0.20
0.19
0.20
0.4
0.28
0.26
0.27
0.5
0.35
0.33
0.34
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 143
(a)
Add the missing label on the diagram.
[1]
(b)
Using the information in the table, describe the relationship between the
concentration of sodium chloride solution and the current.
[1]
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(c)
Using the information in the table, state whether the evidence to support your
answer in (b) is strong or weak. Explain your answer.
[1]
…………………………………………………………………………………………………
…………………………………………………………………………………………………
(d)
(i)
Calculate the mean value for the current using sodium chloride
concentration with a value of 0.5 M.
[1]
mean current = …………………… A
(ii)
Use the formula below to calculate the percentage variation in the
current measured using this solution.
[1]
(furthest value from the mean value – mean value) × 100
mean value
percentage variation = …………………… %
(e)
Calculate the total volume of the stock solution required by the students in
Group A to prepare all five of their solutions.
[2]
volume = …………………… cm3
7
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GCSE CHEMISTRY Sample Assessment Materials 144
5.
Thomas was asked to carry out an experiment to find the formula of an oxide of
copper using the apparatus below.
Thomas weighed the bung and tube. He added the oxide of copper and re-weighed
the bung and tube.
He began heating and passing the methane gas over the oxide. After 5 minutes, he
stopped heating and turned off the gas. He allowed the tube to cool and weighed the
bung, the tube and its contents again. He repeated these steps twice more.
His results are shown in the table.
Mass of bung and tube
20.0 g
Mass of bung, tube and oxide of copper
25.9 g
Mass of bung, tube and contents after 5 minutes
25.1 g
Mass of bung, tube and contents after 10 minutes
24.7 g
Mass of bung, tube and contents after 15 minutes
24.7 g
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GCSE CHEMISTRY Sample Assessment Materials 145
(a)
State why methane gas was passed through the tube.
[1]
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
(b)
Explain why Thomas heated and weighed the tube and its contents several
times.
[1]
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
(c)
(i)
Calculate the mass of oxygen in the oxide of copper.
[1]
mass of oxygen = …………………… g
(ii)
Calculate the empirical formula for this oxide of copper.
Show your working.
[4]
empirical formula ……………………
7
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 146
6.
(a)
The labels have fallen off three bottles. The bottles contain solutions of
sodium bromide, sodium chloride and potassium chloride. It is not known
which bottle is which. Suggest how you identify the three solutions using two
tests.
You will be rewarded for a logical testing sequence in which you carry out the
minimum amount of testing necessary to identify each solution.
Give the observations you would expect for each solution in each test.
Detailed practical details are not required.
[5]
……………………………………………………………………….………………………….
………………………………………………………………....………………………………..
……………………………………………………………….………………………………….
…………………………………………………………….…………………………………….
…………………………………………………………………………………………………..
…………………………………………………………….…………………………………….
…………………………………………………………………………………………………..
…………………………………………………………….…………………………………….
(b)
It is thought that magnesium ions have contaminated a solution containing
barium ions.
Use the information below to develop a method to test for the presence of
magnesium ions in a solution which also contains barium ions.
No other metal ions are present in the solution.
Explain the purpose of each step in the method.
Include the observations you expect to make if magnesium ions are present.
[5]
Compound
sulfuric acid
soluble
barium sulfate
insoluble
barium carbonate
insoluble
magnesium sulfate
magnesium carbonate
© WJEC CBAC Ltd.
Soluble or insoluble?
soluble
insoluble
sodium sulfate
soluble
sodium carbonate
soluble
GCSE CHEMISTRY Sample Assessment Materials 147
……………………………………………………………………….…………………
………………………………………………………………....……………………….
……………………………………………………………….…………………………
…………………………………………………………….……………………………
………………………………………………………………………………………….
……………………………………………………………….…………………………
…………………………………………………………….……………………………
10
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 148
7.
Group 1 compounds are all soluble in water.
Explain how you could prepare crystals of potassium nitrate from an acid and one other
reagent of your choice.
Include a balanced symbol equation in your answer.
[6 QER]
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
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……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
6
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 149
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 150
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GCSE CHEMISTRY Sample Assessment Materials 151
GCSE CHEMISTRY
COMPONENT 2
Applications in Chemistry
HIGHER TIER
RESOURCE BOOKLET
for use in Section A
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GCSE CHEMISTRY Sample Assessment Materials 152
Allotropes of carbon
Carbon exists as a number of different allotropes. Some important allotropes of carbon are
described in this article.
Diagram 1 Diamond and graphite
Diamond
Graphite
The structure of diamond can be related to a cube. The diagram below shows this.
Diagram 2 A unit cubic cell of diamond
c
b
a
The cell dimension a = b = c = 0.36 nm
Diagram 3 Graphene and fullerene
Graphene
© WJEC CBAC Ltd.
Fullerene
GCSE CHEMISTRY Sample Assessment Materials 153
Graphene and fullerenes
Graphene is a single sheet with the carbon atoms arranged in the layer as they are in
graphite.
Fullerenes are cage-like spherical molecules. They were first discovered using a method
known as mass spectroscopy. One fullerene identified by mass spectrometry had a relative
molecular mass of 720.
Carbon nanotubes
Carbon nanotubes are made of graphene sheets rolled into the shape of a cylinder, often
with at least one end closed.
Diagram 4 Carbon nanotube
Properties of carbon nanotubes
The specific strength is a material's tensile strength divided by its density. It is also known
as the strength-to-weight ratio.
Another way to describe specific strength is breaking length which is the maximum length
of a vertical column of the material that could support its own weight when suspended only
at the top.
Table 1
Tensile strength
(MPa)
Density
(g/cm³)
Specific
strength
(kN m/kg)
Breaking length
(km)
stainless steel
505
8.00
63.1
6.4
aluminium
572
2.81
204
20.8
kevlar
3 620
1.44
carbon
nanotube
62 000
1.34
46 268
4 716
Material
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 154
COMPONENT 2 - Applications in Chemistry
HIGHER TIER
MARK SCHEME
GENERAL INSTRUCTIONS
Recording of marks
Examiners must mark in red ink.
One tick must equate to one mark (apart from the questions where a level of response mark scheme is applied).
Question totals should be written in the box at the end of the question.
Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.
Marking rules
All work should be seen to have been marked.
Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.
Crossed out responses not replaced should be marked.
Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.
© WJEC CBAC Ltd.
GCSE CHEMISTRY Sample Assessment Materials 155
Extended response question
A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly,
decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality
of the response. Then decide which mark to award within the levels. Award the higher mark in the level if there is a good match with both the
content statements and the communication statements.
Marking abbreviations
The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded.
cao
ecf
bod
=
=
=
© WJEC CBAC Ltd.
correct answer only
error carried forward
benefit of doubt
GCSE CHEMISTRY Sample Assessment Materials 156
Question
1
(a)
Marking details
Covalent bonding
Each carbon atom shares electron pairs with four other carbon
atoms
AO1
1
AO2
Marks available
AO3
Total
3
Maths
1
C
C
C
1
C
C
(b)
(i)
(1)
Three valence electrons of carbon are used up in forming the
covalent bonds (1)
The fourth electron is delocalized and able to move (1)
(ii)
In graphite, the carbon atoms are arranged in flat parallel layers
attracted to adjacent layers by weak forces (1)
This allows each layer to slide over the other easily (1)
(iii)
0.047 nm3
2
2
2
2
Both answer and unit required
1
© WJEC CBAC Ltd.
1
1
Prac
GCSE CHEMISTRY Sample Assessment Materials 157
Question
(c)
(d)
Marking details
AO1
No carbon atoms = 720/12 (1)
Molecular formula C60 (1) (allow error carried forward)
(i)
(ii)
© WJEC CBAC Ltd.
Marks available
AO3
Total
1
3 620/1.44
= 2 514
Estimate of approx. 251/252 (also allow error carried forward accept value if it is clearly 10:1 ratio of specific strength)
Carbon nanotubes have a much higher strength-to-weight ratio
(1)
So will be stronger and lighter (1)
Question 1 total
AO2
1
Maths
Prac
2
3
3
6
6
3
2
2
3
15
4
0
GCSE CHEMISTRY Sample Assessment Materials 158
Question
2
(a)
Marking details
Separation occurs because the two liquids have different boiling
points (1)
(i)
(ii)
Prac
4
4
1
1
At 78 °C ethanol vapour enters the condenser and becomes liquid
as it is cooled (1)
1
1
Only a small difference between boiling points (1)
1
A large amount of ethanol vapour would also reach the condenser
at the boiling point of compound X / 75 °C (1)
1
2
2
Add fractionating column/ use fractional distillation
1
1
1
Question 2 total
© WJEC CBAC Ltd.
AO2
Ethanol boils at a lower temperature than water (1)
Ethanol is collected in the beaker and water is left in the flask (1)
(b)
AO1
Marks available
AO3
Total Maths
2
4
1
7
0
7
GCSE CHEMISTRY Sample Assessment Materials 159
Question
3
(a)
(b)
(i)
(ii)
(iii)
(iv)
Marking details
reduction since the ions gain electrons
Filtration / filter
AO2
Marks available
AO3
Total
1
1
Maths
Prac
1
All points plotted correctly (2)
Any 3 points plotted correctly (1)
2
Straight line of best fit through the origin – drawn with ruler (1)
1
3
Experimental results below expected results / less copper
formed than expected
1
1
1
2
2
2
2
8
Any two of following for (1) each
Not all the zinc added had reacted
Zinc contains an impurity / is oxidised
Not all copper transferred from beaker to filter
Question 3 total
© WJEC CBAC Ltd.
AO1
1
1
2
4
3
3
3
7
GCSE CHEMISTRY Sample Assessment Materials 160
Question
4
Marking details
AO1
1
AO2
Marks Available
AO3
Total
1
(a)
Electrode
(b)
Any of following for (1)
Higher the concentration of sodium chloride, the higher the
current
Doubling the concentration doubles the current
Current is proportional to concentration
1
1
Evidence is strong because
Results are reproducible / each group has similar results /
each 0.1 M increase in concentration leads to a similar increase
in current
1
1
(c)
(d)
Maths
Prac
1
1
(i)
0.34
1
1
1
(ii)
3.0 / 3
1
1
1
2
2
2
7
4
4
(e)
© WJEC CBAC Ltd.
Calculation showing ratio required for any of
0.1, 0.2, 0.3 or 0.4 M solutions e.g.
0.1 × 50 (1)
0.5
1
150 (1)
1
Question 4 total
2
3
2
GCSE CHEMISTRY Sample Assessment Materials 161
Question
5
Marking details
AO1
1
AO2
Marks Available
AO3
Total
1
(a)
Methane is the reducing agent / reacts with the oxide
(b)
To ensure that the reaction was complete
1
1
(i)
1.2
1
1
(ii)
Mass of copper = 4.7 (1)
1
(c)
Cu 4.7
64
O 1.2
16
(1)
Maths
Prac
1
1
1
1
Cu : O ratio is 0.73 : 0.75
Therefore empirical formula is CuO (1)
1
4
4
7
4
Working must be shown
Question 5 total
© WJEC CBAC Ltd.
4
3
0
2
GCSE CHEMISTRY Sample Assessment Materials 162
Question
6
(a)
Marking details
Flame test (1)
NaBr & NaCl give yellow orange flame - KCl gives lilac flame.
(both observations for 1 mark).The KCl solution is identified
Add dilute silver nitrate solution to the remaining solutions (1)
NaBr gives cream precipitate (1)
NaCl gives white precipitate (1)
AO1
AO2
1
Marks available
AO3
Total
Maths
Prac
5
5
4
5
5
4
10
1
1
2
Award full marks for above. If candidate as added extra
unnecessary test (i.e. test for KCl twice) then maximum mark
possible is 4
Alternative approach involves reversing testing
sequence:
Add dilute silver nitrate solution to the solutions (1)
NaCl and KCl give a white precipitate (1)
NaBr gives cream precipitate (1) NaBr identified
Flame test (1)
NaCl gives orange flame & KCl a lilac flame (1)
(b)
© WJEC CBAC Ltd.
Award full marks for above. If candidate as added extra
unnecessary test (i.e. test for NaBr twice) then maximum
mark possible is 4
The first step is to remove barium ions from the solution so
that we can test for Mg2+ without Ba2+ ions interfering (1)
1. Add sodium sulfate solution to the test solution (1)
Precipitate of barium sulfate formed which can be
removed by filtration. (1)
2. Add sodium carbonate to the solution from step 2 to test for
magnesium ions (1)
3. White precipitate of magnesium carbonate seen if
magnesium ions are present (1)
1
Question 6 total
4
2
0
10
GCSE CHEMISTRY Sample Assessment Materials 163
Question
7
Marking details
Indicative content:
AO1 allocation Reagents: nitric acid and potassium hydroxide
DescriptionUse titration
Measure known volume of one reagent into conical flask using
pipette, add indicator solution
Add other reagent steadily from burette whilst swirling flask, add
dropwise near to end-point, record volume of reagent needed for
colour change
Repeat reaction using identical volumes of both solutions but
without indicator
Heat solution to reduce volume/evaporate, leave to crystallise
AO2 allocation Explanation
Titration used since both reagents are soluble in water so need to
use titration to exactly neutralise acid and alkali. This way the
solution will not contain unreacted acid or alkali which otherwise
cannot be easily separated.
Equation KNO3 + HCl  KCl + H2O (AO2)
5 - 6 marks: Correct apparatus named, suitable volume of first
reagent given, indicator and colour change specified, good detail
for evaporation stage.
There is a sustained line of reasoning which is coherent,
substantiated and logically structure. The information included in
the response is relevant to the argument.3 - 4 marks: At least one
piece of apparatus named, reaction repeated without indicator,
reference to evaporation stage.
There is a line of reasoning which is partially coherent, supported
by some evidence and with some structure. Mainly relevant
information is included in the response but there may be some
minor errors or the inclusion of some information not relevant to the
argument
© WJEC CBAC Ltd.
AO1
AO2
Marks Available
AO3
Total
Maths
Prac
2
4
6
6
GCSE CHEMISTRY Sample Assessment Materials 164
1 - 2 marks: Reagents named, reference to use of indicator and
crystallisation.
There is a basic line of reasoning which is not coherent,supported
by limited evidence and with very little structure. There may be
significant errors or the inclusion of information not relevant to the
argument.
0 marks: No attempt made or no response worthy of credit.
Question 7 total
© WJEC CBAC Ltd.
4
2
0
6
0
6
GCSE CHEMISTRY Sample Assessment Materials 165
COMPONENT 2 - Applications in Chemistry
HIGHER TIER
SUMMARY OF MARKS ALLOCATED TO ASSESSMENT OBJECTIVES
Question
AO1
AO2
AO3
TOTAL MARK
MATHS
PRAC
1
6
6
3
15
4
0
2
2
4
1
7
0
7
3
2
4
2
8
3
7
4
2
3
2
7
4
4
5
4
3
0
7
4
2
6
4
2
4
10
0
10
7
4
2
0
6
0
6
TOTAL
24
24
12
60
15
36
WJEC Eduqas GCSE Chemistry SAMs from 2016/ED/EM
14/12/15
© WJEC CBAC Ltd.