Edexcel GCSE
Chemistry
Unit C2: Discovering chemistry
Foundation Tier
Sample Assessment Material
Time: 1 hour
Paper Reference(s)
5CH2F/01
You do not need any other materials.
Total Marks
Instructions
• Use black ink or ball-point pen.
• Fill in the boxes at the top of this page with your name,
centre number and candidate number.
• Answer all questions.
• Answer the questions in the spaces provided
– there may be more space than you need.
• Some questions must be answered with a cross in a box (6). If you
change your mind about an answer, put a line through the box (6) and
then mark your new answer with a cross (6).
Information
• The total mark for this paper is 60.
• The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Questions labelled with an asterisk (*) are ones where the quality of
your written communication will be assessed
– you should take particular care with your spelling, punctuation and
grammar, as well as the clarity of expression, on these questions.
Advice
•
•
•
•
Read each question carefully before you start to answer it.
Keep an eye on the time.
Try to answer every question.
Check your answers if you have time at the end.
2
*H34056A0212*
59
Co
59
Ni
63.5
Cu
65
Zn
39
139
La*
57
[227]
Ac*
strontium
38
137
Ba
barium
56
[226]
Ra
radium
88
133
Cs
caesium
55
[223]
Fr
francium
87
dubnium
105
106
seaborgium
[266]
Sg
[262]
Db
104
74
tungsten
107
bohrium
[264]
Bh
75
rhenium
186
Re
43
184
W
technetium
42
[98]
Tc
molybdenum
73
tantalum
181
Ta
41
niobium
rutherfordium
[261]
Rf
72
hafnium
178
Hf
40
zirconium
96
Mo
108
hassium
[277]
Hs
76
osmium
190
Os
44
ruthenium
101
Ru
26
109
meitnerium
[268]
Mt
77
iridium
192
Ir
45
rhodium
103
Rh
27
110
darmstadtium
[271]
Ds
78
platinum
195
Pt
46
palladium
106
Pd
28
111
roentgenium
[272]
Rg
79
gold
197
Au
47
silver
108
Ag
29
81
thallium
204
Tl
49
indium
115
In
31
gallium
82
lead
207
Pb
50
tin
119
Sn
32
germanium
83
bismuth
209
Bi
51
antimony
122
Sb
33
arsenic
75
As
15
phosphorus
31
P
7
nitrogen
14
N
84
polonium
[209]
Po
52
tellurium
128
Te
34
selenium
79
Se
16
sulfur
32
S
8
oxygen
16
O
85
astatine
[210]
At
53
iodine
127
I
35
bromine
80
Br
17
chlorine
35.5
Cl
9
fluorine
19
F
The relative atomic masses of copper and chlorine have not been rounded to the nearest whole number.
86
radon
[222]
Rn
54
xenon
131
Xe
36
krypton
84
Kr
18
argon
40
Ar
10
neon
20
Ne
Elements with atomic numbers 112-116 have been reported but not fully
authenticated
80
mercury
201
Hg
48
cadmium
112
Cd
30
73
Ge
14
silicon
28
Si
27
Al
aluminium
6
carbon
12
C
5
* The lanthanoids (atomic numbers 58-71) and the actinoids (atomic numbers 90-103) have been omitted.
89
actinium
lanthanum
yttrium
93
Nb
25
zinc
37
91
Zr
24
chromium
copper
rubidium
89
Y
23
vanadium
nickel
88
Sr
22
titanium
52
Cr
cobalt
85
Rb
21
51
V
iron
20
19
48
Ti
manganese
calcium
potassium
scandium
70
Ga
40
Ca
39
K
56
Fe
12
11
55
Mn
magnesium
sodium
45
Sc
13
24
Mg
23
Na
atomic (proton) number
boron
4
name
beryllium
3
11
B
2
0
helium
7
1
6
hydrogen
lithium
relative atomic mass
atomic symbol
Key
5
4
He
4
1
H
3
9
Be
2
7
Li
1
The Periodic Table of the Elements
Leave
blank
Atoms of elements
1.(a) The diagram shows the particles in a lithium atom.
Use the diagram to complete the table below for this atom.
number of protons
mass number
(2)
(b) Which row of the table shows the charges on a proton, a neutron and an electron?
proton
neutron
electron
A 6 positive
negative
no charge
B
6 positive
no charge negative
C
6 negative no charge positive
D 6 positive
positive
negative
(1)
(c) Lithium is a metal.
How can you tell this by looking at the periodic table?
(1)
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(d) Protons and neutrons have a relative mass of 1 and electrons have a relative mass of
1/1836.
Use this information to explain why most of the mass of an atom is concentrated in the
nucleus.
(2)
(e) When Mendeleev produced his periodic table, he left a gap between silicon and tin and
predicted the properties of the element that would fit in the gap.
Explain why Mendeleev left this gap and what information he used to predict the
properties of the missing element.
(2)
(Total for Question 1 = 8 marks)
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Rates of reaction
2. Some chemical reactions are fast and some are slow.
frying an egg
a firework exploding
an iron nail rusting
paper burning
hydrochloric acid on marble chips
(a) Which reaction in the box above is the fastest reaction?
(1)
(b) Charlotte investigated the rate of reaction between magnesium ribbon and excess
dilute hydrochloric acid. The reaction produces hydrogen gas.
She used the equipment shown in the diagram to carry out four experiments, A, B, C
and D.
She only changed the temperature of the acid each time.
The graph shows her results.
Leave
blank
(i) Which experiment had the fastest rate?
(1)
(ii) Which experiment has not finished?
(1)
(iii) Which of these could Charlotte use to speed up the reaction?
A 6 more of the same acid
B 6 less magnesium
C 6 smaller pieces of magnesium with the same total mass
D 6 a smaller conical flask
(1)
(c)(i)
Omar investigated the use of possible catalysts in a chemical reaction.
He carried out the reaction without a catalyst.
He then carried out the same reaction a further three times. In each of these three
experiments he added a small amount of X, Y or Z.
The results are shown in the table.
substance added
none
time to complete reaction (s)
120
X
10
Y
118
Z
118
Use these results to explain why X could be a catalyst but Y and Z are probably not
catalysts.
(2)
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(ii) Catalytic converters are used in many cars.
They are fitted in the exhaust system to convert harmful gases into less harmful
ones.
Explain why the catalytic converter works better when the exhaust system is hot.
(2)
(Total for Question 2 = 8 marks)
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Separation
3. Metal tokens are used to operate a car wash.
The owners suspect that some fake tokens are being used.
A chemist checked which metals were in the tokens using paper chromatography.
The diagram shows the chromatogram the chemist obtained.
(a) (i) Use evidence from the chromatogram to explain, in detail, how the chemist knows
that tokens A and B are fake.
(2)
(ii) Calculate the Rf value for copper.
Rf = …………………………………………
(2)
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(b) Water is often used as a solvent.
The diagram shows the electrons in a water molecule.
On the oxygen atom, only the outer electrons are shown.
(i) What type of bond is present in a water molecule?
(1)
(ii) Explain how this type of bond forms.
(2)
(iii) Water has a low boiling point of 100°C.
Explain why water has a low boiling point.
(2)
(c) Water and hexane are immiscible.
These two liquids should be separated using
A 6 paper chromatography
B 6 a filter funnel and filter paper
C 6 a separating funnel
D 6 precipitation
(1)
(Total for Question 3 = 10 marks)
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Making compounds
4. Edward was making magnesium oxide by heating magnesium in a crucible.
(a) Occasionally, during the experiment, Edward lifted the lid of the crucible for a few
seconds.
(i) Why did he lift the lid during the experiment?
(1)
(ii) The reaction is exothermic.
An exothermic reaction is a reaction in which
A 6 two substances react to form one substance
B 6 energy is taken in
C 6 bonds are broken but new bonds are made
D 6 energy is given out
(1)
(iii) Complete and balance this equation for the reaction.
………………………………
+ ……………………………… → ………………MgO
(2)
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(iv) Calculate the relative formula mass of magnesium oxide, MgO.
(Relative atomic masses: Mg = 24, O = 16)
(1)
(b) These are Edward’s results.
mass
mass
mass
mass
mass
of crucible
of crucible +
magnesium
of crucible +
magnesium oxide
of magnesium
of magnesium oxide
= 12.00 g
= 12.24 g
= 12.32 g
= 0.24 g
= 0.32 g
The theoretical yield for this reaction was 0.40 g.
Calculate the percentage yield for Edward’s experiment.
yield = …………………………………….%
(2)
(c) Explain why it is important when making compounds in industry that the production
of waste products is kept to a minimum.
(3)
(Total for Question 4 = 10 marks)
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Salts
5. Potassium chloride is an ionic solid made up of potassium ions and chloride ions.
The diagram shows the structure of potassium chloride.
(a) Describe the formation of potassium ions and chloride ions from potassium atoms and
chlorine atoms.
(2)
(b) Which of these is most likely to be the melting point of potassium chloride?
A 6
–8°C
B 6
8°C
C 6
80°C
D 6 800°C
(1)
(c) What colour flame would be produced by potassium chloride in a flame test?
(1)
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(d) Explain why a precipitate forms when silver nitrate solution is added to sodium chloride
solution.
(2)
*(e) Lead iodide is an insoluble salt.
Describe the steps needed to prepare a pure, dry sample of lead iodide from solutions
of lead nitrate and potassium iodide.
Your description should include safety precautions.
(6)
(Total for Question 5 = 12 marks)
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Elements in the periodic table
6. Helium is a gas that is used to fill balloons so that they rise in the air.
(a) Early gas-filled balloons contained hydrogen.
Why is it safer to use helium instead of hydrogen?
(1)
(b) (i) The table contains information about helium and other elements in group 0 of the
periodic table.
name
helium
neon
argon
krypton
atomic number density (g dm–3) boiling point (°C)
2
0.17
–269
10
0.84
–246
18
1.66
–186
36
3.46
–153
The density of air is 1.21 g dm-3
Explain why helium, instead of any other gas from group 0, is used to fill balloons.
(2)
(ii)
Why does helium not form compounds?
(2)
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(c) Sodium and potassium are metallic elements.
Solid sodium and potassium conduct electricity because
A 6 they contain ions that move
B 6 they contain delocalised electrons that move
C 6 the electrons knock into each other passing on the current
D 6 friction between electrons and ions generates electricity
(1)
*(d) Both sodium and potassium react with water.
Compare the similarities and differences between the reactions of the two metals with
water.
(6)
(Total for Question 6 = 12 marks)
TOTAL FOR PAPER = 60 MARKS