Download Chemistry SAM

GCE
CCEA GCE Specimen
Assessment Material for
Chemistry
For first teaching from September 2016
For first award of AS level in Summer 2017
For first award of A level in Summer 2018
Subject Code: 1110
BLANK PAGE
Foreword
CCEA has developed new specifications which comply with criteria for GCE qualifications.
The specimen assessment materials accompanying new specifications are provided to give
centres guidance on the structure and character of the planned assessments in advance of
the first assessment. It is intended that the specimen assessment materials contained in
this booklet will help teachers and students to understand, as fully as possible, the markers’
expectations of candidates’ responses to the types of tasks and questions set at GCE level.
These specimen assessment materials should be used in conjunction with CCEA’s GCE
Chemistry specification.
BLANK PAGE
GCE Chemistry
Specimen Assessment Materials
Contents
Specimen Papers
3
Assessment Unit AS 1: Basic Concepts in Physical and Inorganic Chemistry
3
Assessment Unit AS 2: Further Physical and Inorganic Chemistry and an
Introduction to Organic Chemistry
Assessment Unit AS 3: Basic Practical Chemistry – Practical Booklet A
25
Assessment Unit AS 3: Basic Practical Chemistry – Practical Booklet B
Assessment Unit A2 1: Further Physical and Organic Chemistry
Assessment Unit A2 2: Analytical, Transition Metals, Electrochemistry and
Organic Nitrogen Chemistry
Assessment Unit A2 3: Further Practical Chemistry – Practical Booklet A
Assessment Unit A2 3: Further Practical Chemistry – Practical Booklet B
53
65
89
113
123
Apparatus and Materials Lists
135
Assessment Unit AS 3: Basic Practical Chemistry – Practical Booklet A
Assessment Unit A2 3: Further Practical Chemistry – Practical Booklet A
137
145
Mark Schemes
155
General Marking Instructions
Assessment Unit AS 1: Basic Concepts in Physical and Inorganic Chemistry
Assessment Unit AS 2: Further Physical and Inorganic Chemistry and an
Introduction to Organic Chemistry
Assessment Unit AS 3: Basic Practical Chemistry – Practical Booklet A
Assessment Unit AS 3: Basic Practical Chemistry – Practical Booklet B
Assessment Unit A2 1: Further Physical and Organic Chemistry
Assessment Unit A2 2: Analytical, Transition Metals, Electrochemistry and
Organic Nitrogen Chemistry
Assessment Unit A2 3: Further Practical Chemistry – Practical Booklet A
Assessment Unit A2 3: Further Practical Chemistry – Practical Booklet B
157
161
167
45
175
177
181
189
195
199
Subject Code
QAN AS
QAN A2
1110
601/8511/9
601/8512/0
A CCEA Publication © 2016
You may download further copies of this publication from www.ccea.org.uk
SPECIMEN PAPERS
DIVIDER FRONT
SPECIMEN PAPERS
DIVIDER BACK
Centre Number
Candidate Number
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 1
Basic Concepts in Physical
and Inorganic Chemistry
[CODE]
SPECIMEN PAPER
TIME
1 hour 30 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all sixteen questions.
For Examiner’s
use only
Question
Marks
Number
INFORMATION FOR CANDIDATES
The total mark for this paper is 90.
Figures in brackets printed down the right-hand side of pages indicate
the marks awarded to each question or part question.
Quality of written communication will be assessed in Question 16(b)(i)
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
  Section A
 1–10
Section B 
11
12
13
14
15
16
Total
Marks
3
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
16
VI VII O
2
20
18
15
19
10
40
17
14
16
9
35.5
18
84
13
14
8
32
17
80
12
12
7
31
16
79
36
131
11
11
6
28
15
75
35
127
10
5
27
14
73
34
128
9
13
70
33
122
54
[222]
8
65
32
119
53
[210]
7
64
31
115
52
[209]
6
59
30
112
51
209
5
59
29
108
50
207
4
56
28
106
49
204
3
55
27
103
48
201
86
2
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
140
105
59
[231]
141
106
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
58
92
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
4
Data Leaflet
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
5
Section A – Multiple Choice
Select the correct response in each case and mark its code letter by
connecting the dots as illustrated on the answer sheet.
Each multiple choice question is worth 1 mark.
1
In which species is the number of electrons equal to the number of neutrons?
ABe
BF–
CNa
DO2–
2
Which of the following states the name of a suitable indicator, together with the correct
colour change at the end point, for the titration of ethanoic acid with sodium hydroxide
solution?
sodium hydroxide solution
ethanoic acid + indicator
indicator
© CCEA
colour change at end point
A Methyl orange
yellow to red
B Methyl orange
red to yellow
C Phenolphthalein
colourless to pink
D Phenolphthalein
pink to colourless
6
3
Gallium nitride, GaN, is an ionic compound. The electronic configuration of the nitride ion in
gallium nitride is:
A1s2 2s2
B1s2 2s2 2p3
C1s2 2s2 2p4
D1s2 2s2 2p6
4 Which of the following is the best oxidising agent?
ACl2
BCI–
CI2
DI–
5
Which of the following atoms obeys the octet rule?
A
B Be in BeCl42–
C P in PCl5
D S in SF6
6
Which of the following does not have hydrogen bonding between its molecules?
B in BF3
ACHF3
BC2H5OH
CHF
DNH3
7
7
Which of the following is a polar molecule?
ABF3
BCCl4
CCS2
DNCl3
8
In the Periodic Table the element zinc belongs to:
A
B the f block
C the p block
D the s block
9
The relative atomic mass is defined as:
A
B the average mass of an element relative to
C the mass of an atom of an element relative to
D the mass of an atom of an element relative to the mass of a hydrogen atom
the d block
the average mass of an atom of an element relative to
atom
1
12
1
12
of the mass of a carbon-12
of the mass of a carbon atom
1
12
of the mass of an atom of carbon-12
10 Which of the following is not produced when concentrated sulfuric acid reacts with sodium
bromide?
Abromine
B hydrogen bromide
C hydrogen sulfide
D sulfur dioxide
8
Section B
Examiner Only
Marks Re-mark
Answer all six questions in this section
11 Electrons are found in shells, sub-shells and orbitals.
(a)(i) Explain what is meant by the term orbital.
[1]
(ii) Draw the shape of an s orbital.
[1]
(iii) Write the electronic configuration for an atom of copper.
[1]
9
[Turn over
(b) Successive ionisation energies provide evidence for the existence of
different shells in an atom.
(i) On the axes below, sketch a graph of the successive ionisation
energies of oxygen.[2]
log
ionisation
energy
0
1
2
3
4
5
6
7
8
number of electrons removed
(ii) Write an equation, including state symbols, to represent the
second ionisation energy of oxygen.
[1]
(iii) Explain why the first ionisation energy of oxygen is less than the
first ionisation energy of fluorine.
[3]
10
Examiner Only
Marks Re-mark
(c) Ionisation energies provide evidence for the order of elements in the
Periodic Table.
Examiner Only
Marks Re-mark
The ionisation energies of some Group VI elements are shown in the
table below.
element
ionisation energy/kJ mol–1
Oxygen
1314
Sulfur
1000
Selenium
941
Tellurium
869
State and explain the trend in ionisation energies in this group.
11
[4]
[Turn over
12 Uranium, named after the planet Uranus, is a weakly radioactive metal
used to fuel nuclear power plants. Uranium has properties and a structure
typical of a metal.
(a) Describe the structure of uranium metal.
[2]
(b) The two most common isotopes of uranium are U235 and U238.
(i) Explain why U235 and U238 are isotopes.
[2]
(ii) The relative atomic mass of a sample of uranium containing the
isotopes U235 and U238 is 237.979.
Calculate the percentage abundance of each isotope present in
the sample.
[3]
12
Examiner Only
Marks Re-mark
(c) The extraction of uranium from its ore can be represented by the
following series of reactions.
HNO3
Ore →
UO2(NO3)2
U
(i) Write an equation for the conversion of UF4 to U.
[2]
(ii) Write an equation for the conversion of UO2 to UF4.
Marks Re-mark
heat H2HF Mg
→
UO3
→
UO2
→
UF4
→
Examiner Only
[2]
(iii) Complete the table below.
compound
oxidation state of uranium
UO2(NO3)2
UO3
UF4
[3]
(d) Uranyl nitrate, UO2(NO3)2, thermally decomposes to produce uranium
trioxide.
UO2(NO3)2 → 2UO3  4NO2  O2
(i) What is the systematic name for NO2?
[1]
(ii) How would you show experimentally that oxygen was given off in
this decomposition?
13
[1]
[Turn over
13 Boron nitride has the chemical formula BN and exists in two physical
forms. The structures of these forms, A and B, are shown below, and they
closely resemble the two allotropes of carbon.
Structure A
Structure B
Source: Adapted from Cambridge O Level Chemistry 5070 Paper 2 QA2 June 2009.
Reproduced by permission of Cambridge International Examinations.
Boron nitride is used as a lubricant in pencil leads and is also used in
cutting tools and drill bits.
(a)Suggest why boron nitride with structure A can be used in pencil
leads.
[2]
(b) Suggest why boron nitride with structure B is hard.
[2]
(c)Suggest why boron nitride with structure B does not conduct
electricity.
14
[1]
Examiner Only
Marks Re-mark
14 Sunglasses can be made from photochromic glass which contains small
amounts of silver(I) chloride and copper(I) chloride. As sunlight passes
through the glass the silver ions are reduced to silver atoms which cluster
together and block the transmittance of light resulting in the darkening of
the glass. The chloride ions are oxidised to chlorine atoms.
Examiner Only
Marks Re-mark
(a)(i) Calculate the maximum mass of silver ions that can be formed
from 0.287 g of silver(I) chloride.
[2]
(ii) Write an equation for the reduction of silver ions to silver atoms.
[1]
(b) When exposure to light ends, the chlorine atoms are reduced by the
copper(I) ions into chloride ions, and the copper(II) ions produced then
react with the silver atoms.
Write an ionic equation for the reaction of copper(I) ions with chlorine
atoms.
[1]
(c) Copper(I) chloride, similar to that used in photochromic glass, can be
prepared in the laboratory by reacting copper metal with copper(II)
oxide and concentrated hydrochloric acid. The equation for the
reaction is:
2HCl  CuO  Cu → 2CuCl  H2O
(i) Explain, using oxidation numbers, why this is a disproportionation
reaction.
[3]
(ii) Suggest why the copper(I) chloride forms as a precipitate in this
reaction.
15
[1]
[Turn over
(d) Copper(II) chloride can be produced in the laboratory by the reaction
of copper(II) carbonate with hydrochloric acid.
Calculate the volume of 1.0 M hydrochloric acid needed to react with
copper(II) carbonate to produce 2.0 g of copper(II) chloride. Give
your answer to 2 significant figures.
[3]
16
Examiner Only
Marks Re-mark
15 An interhalogen compound is a molecule containing two or more different
halogen atoms.
Examiner Only
Marks Re-mark
(a) Chlorine trifluoride is an interhalogen compound with the formula ClF3.
It was first prepared in 1930 by the reaction of chlorine with fluorine.
(i) Write an equation for the preparation of chlorine trifluoride.
[1]
(ii) Chlorine trifluoride bonds covalently.
Explain the meaning of the term covalent bond.
[2]
(iii) Draw a dot and cross diagram to show the bonding in chlorine
trifluoride.
17
[2]
[Turn over
(b) Chlorine trifluoride reacts with arsenic pentafluoride as shown in the
following equation:
Examiner Only
Marks Re-mark
ClF3  AsF5 → ClF2  AsF6–
(i) Draw and name the shapes of AsF5 and ClF2. Explain the shape
of each molecule.
AsF5
Name
ClF2
Name
[6]
(ii) Predict the bond angle in the ClF2 ion.
[1]
18
(c) Saturated fats contain single covalent bonds. Iodine monochloride is
an interhalogen molecule used to determine how saturated a fat is.
Examiner Only
Marks Re-mark
(i) Show the polarity of the iodine-chlorine bond on the diagram
below and explain why the bond is polar.
I–Cl
[2]
(ii) Explain why iodine monochloride has a higher boiling point than
chlorine.
19
[4]
[Turn over
16 Sodium iodide is used to prevent iodine deficiency in the body. Iodised
table salt contains one part sodium iodide to 100 000 parts of sodium
chloride. Magnesium carbonate is also present as an anticaking agent.
(a) Describe how you could use chemical tests on a sample of iodised
table salt, to prove that it contains sodium ions, halide ions and
carbonate ions.
[4]
20
Examiner Only
Marks Re-mark
(b)(i) Sodium reacts with iodine to form sodium iodide.
Examiner Only
Marks Re-mark
2Na  I2 → 2NaI
The melting points of each of these substances are shown in the
table below.
solid
melting point/°C
sodium
98
iodine
114
sodium iodide
662
Explain why there is a difference in the melting points of sodium,
iodine and sodium iodide.
In your answer refer to the type of particle involved and the nature
and relative strength of the attractive forces holding the particles
together.
In this question you will be assessed on using your written
communication skills including the use of specialist
scientific terms.
21
[6]
[Turn over
(ii) State the colour of solid iodine and that of solid sodium iodide.
Examiner Only
Marks Re-mark
Iodine
Sodium iodide
_[2]
(c) Sodium iodide is produced in the reaction between iodine and sodium
hydroxide.
Write an equation for this reaction.
[2]
(d)
A sodium iodide solution was made in the laboratory by dissolving
46.0 g of sodium iodide in 25.0 g of water at 20 °C.
(i) Calculate the molarity of this sodium iodide solution. Give your
answer to 3 significant figures.
[2]
(ii) Chlorine was bubbled through the sodium iodide solution.
State the colour change observed in the solution.
From
to
22
[1]
THIS IS THE END OF THE QUESTION PAPER
23
BLANK PAGE
24
Centre Number
Candidate Number
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 2
Further Physical and Inorganic Chemistry
and an Introduction to Organic Chemistry
[CODE]
SPECIMEN PAPER
TIME
1 hour 30 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all sixteen questions.
For Examiner’s
use only
Question
Marks
Number
INFORMATION FOR CANDIDATES
The total mark for this paper is 90.
Figures in brackets printed down the right-hand side of pages indicate
the marks awarded to each question or part question.
Quality of written communication will be assessed in Question 13(c)(i).
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
Section A
 1–10
Section B
11
12
13
14
15
16
Total
Marks
25
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
16
VI VII O
2
20
18
15
19
10
40
17
14
16
9
35.5
18
84
13
14
8
32
17
80
12
12
7
31
16
79
36
131
11
11
6
28
15
75
35
127
10
5
27
14
73
34
128
9
13
70
33
122
54
[222]
8
65
32
119
53
[210]
7
64
31
115
52
[209]
6
59
30
112
51
209
5
59
29
108
50
207
4
56
28
106
49
204
3
55
27
103
48
201
86
2
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
140
105
141
106
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
58
59
[231]
92
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
26
Data Leaflet
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
27
Section A – Multiple Choice
Select the correct response in each case and mark its code letter by connecting the dots
as illustrated on the answer sheet.
Each multiple choice question is worth 1 mark.
1
The enthalpy change for the formation of ammonia is –46.2 kJ mol–1. What is the enthalpy
change, in kJ, for the reaction 2NH3(g) → N2(g)  3H2(g)?
A–46.2
B
46.2
C
92.4
D–92.4
2
How many structural isomers of C4H10 exist?
A2
B3
C4
D5
3
A radical is a particle with:
A
B a negative charge
C a positive charge
D a lone pair of electrons
an unpaired electron
4 Which of the following molecules has the highest boiling point?
ACH2CH2
BCH3CH2OH
CCH3Cl
DCH3CH2CH3
28
5
Which of the following isomeric alcohols is resistant to oxidation?
A2-methylbutan-1-ol
B2-methylbutan-2-ol
Cpentan-1-ol
Dpentan-2-ol
6
Which of the following has a higher thermal stability than strontium carbonate?
A Barium carbonate
B Beryllium carbonate
C Calcium carbonate
D Magnesium carbonate
7
What volume of oxygen is required for the complete combustion of 100 cm3 of butane at
room temperature and pressure?
A
400 cm3
B
500 cm3
C
650 cm3
D
1300 cm3
8
The reaction between ethene molecules is described as:
Aelimination
Boxidation
Cpolymerisation
Dsubstitution
29
9
The standard conditions referred to when calculating enthalpy changes are:
A 1 kPa and 273 K
B 100 kPa and 273 K
C 100 Pa and 298 K
D 100 kPa and 298 K
10 Which of the following decreases as Group II is descended from magnesium to barium?
A Atomic radius
B First ionisation energy
C Reactivity with water
D Solubility of the hydroxides
30
Section B
Examiner Only
Marks Re-mark
Answer all six questions in this section
11 Analysis of a compound, which contains carbon, hydrogen and bromine
only, showed that 22.2% of its mass is carbon and 3.7% is hydrogen. The
relative molecular mass of the compound is 216.0.
Calculate the molecular formula of the compound.
31
[3]
[Turn over
12 Petrol and diesel are both mixtures of hydrocarbons obtained from crude
oil. Isomers of C5H12 are often included due to their capacity to prevent
knocking, a problem which can lead to severe engine damage. The three
structural isomers of C5H12 are shown below.
name
skeletal formula
n-pentane
isopentane
neopentane
© CCEA
(a) Draw the structural formulae for isopentane and neopentane and give
their IUPAC names.
[4]
(b) The three pentanes are regarded as structural isomers.
Explain this term.
[2]
32
Examiner Only
Marks Re-mark
(c) State and explain which isomer has the lowest boiling point.
Examiner Only
Marks Re-mark
[3]
(d) When ignited in a car engine, the hydrocarbons in the fuel undergo
combustion.
Write an equation for the complete combustion of a pentane molecule.
[2]
(e) In the presence of ultraviolet light, alkanes undergo a radical
substitution reaction.
Outline the mechanism of the reaction between pentane and chlorine
in terms of initiation, propagation and termination steps.
Initiation
Propagation Termination
33
[4]
[Turn over
13 Many enthalpy changes, including enthalpies of combustion, can be
determined by experiment. Others can be deduced using Hess’s Law.
Examiner Only
Marks Re-mark
(a)(i)State Hess’s Law.
[2]
(ii) Define the term standard enthalpy of combustion.
[3]
(iii) Use the standard enthalpies of formation given in the table below
to calculate the enthalpy change for the complete combustion of
methane:
CH4  2O2 → CO2  2H2O
compound
fH
/kJ mol–1
⦵
CO2
–394
H 2O
–286
CH4
–75
[2]
34
(b) Enthalpy changes can also be calculated using average bond
enthalpies. When bond enthalpies were used to estimate the enthalpy
of reaction for the complete combustion of methane, it was found to
have a value of –698 kJ mol–1.
Examiner Only
Marks Re-mark
(i) Explain why the value given above differs from the value obtained
in (a)(iii).
[1]
(ii) Using the estimated enthalpy of reaction and the bond enthalpies
given in the table below, calculate the bond enthalpy of the C–H
bond in methane.
bond
bond enthalpy/kJ mol–1
C O
743
O O
496
H
463
O
35
[3]
[Turn over
(c)(i) Describe how you would experimentally determine the enthalpy of
combustion of ethanol. Include in your answer the apparatus you
would use, the measurements to be taken and how you would use
your results to determine the enthalpy of combustion of ethanol.
In this question you will be assessed on using your written
communication skills including the use of specialist
scientific terms.
[6]
(ii) Give two practical reasons why the experimental value obtained
for the enthalpy of combustion of ethanol is significantly different
from a value quoted in a data book.
[2]
36
Examiner Only
Marks Re-mark
14 The diagram shows a Maxwell-Boltzmann distribution curve for a mixture
of sulfur dioxide and oxygen at temperature T.
Examiner Only
Marks Re-mark
Ea  activation energy
Number of
molecules
with a
given energy
Ea
Energy
© CCEA
(a) On the diagram, sketch the distribution curve for the same mixture at
a higher temperature.
[2]
(b) Use these distribution curves to explain why the reaction between
sulfur dioxide and oxygen is faster at the higher temperature.
[2]
(c) Use the distribution curve to explain the role of a catalyst and why the
reaction between sulfur dioxide and oxygen is faster in the presence
of a catalyst.
37
[4]
[Turn over
15 Halogenoalkanes are a useful class of organic compounds as they can
undergo a number of important reactions.
Examiner Only
Marks Re-mark
(a) Bromoethane can be produced by an electrophilic addition reaction
between ethene and hydrogen bromide.
(i) Explain why hydrogen bromide can be considered as an
electrophile.
[2]
(ii) Draw a flow scheme to show the mechanism for the reaction
between ethene and hydrogen bromide.
[4]
38
(b) When the reaction is repeated with 3-methylpent-2-ene a mixture of
two halogenoalkane products is obtained.
Examiner Only
Marks Re-mark
(i) 3-methylpent-2-ene exists as geometric isomers.
Draw and label the E and Z isomers of the alkene.
[2]
(ii) Draw the structures of the two products obtained when hydrogen
bromide reacts with 3-methylpent-2-ene and indicate the major
and minor products.
[2]
(iii) Explain why the two halogenoalkane products in (ii) are not
obtained in equimolar amounts.
39
[3]
[Turn over
(c) The halogenoalkane, 2-bromobutane, reacts with aqueous sodium
hydroxide to form butan-2-ol.
Examiner Only
Marks Re-mark
(i) Write an equation for the reaction between 2-bromobutane and
sodium hydroxide.
[2]
(ii) Classify butan-2-ol as primary, secondary or tertiary, explaining
your reasoning.
[2]
(d) When 2-bromobutane reacts with ethanolic sodium hydroxide, two
alkene products are formed, one of which is but-1-ene.
(i) Write an equation for the reaction between 2-bromobutane and
ethanolic sodium hydroxide to form but-1-ene.
[2]
(ii) Explain what is meant by the term ethanolic.
[1]
(iii) State the type of reaction between 2-bromobutane and ethanolic
sodium hydroxide.
[1]
(iv) Name the other alkene that is produced in this reaction.
[1]
40
16
The second stage in the production of nitric acid involves the reaction of
nitrogen monoxide with oxygen to form nitrogen dioxide. When nitrogen
monoxide and oxygen are mixed under suitable conditions a dynamic
equilibrium is established.
2NO(g)  O2(g)
2NO2(g)
Examiner Only
Marks Re-mark
∆H  –116 kJ mol–1
(a) Explain what is meant by the term dynamic equilibrium.
[2]
(b) State and explain how increasing the pressure will affect the
equilibrium yield of nitrogen dioxide.
[2]
(c) State and explain how increasing the temperature will affect the
equilibrium yield of nitrogen dioxide.
[2]
(d) State and explain the effect a catalyst has on the equilibrium yield of
nitrogen dioxide.
41
[2]
[Turn over
(e) The position of the equilibrium is found to lie to the right, resulting in a
high yield of nitrogen dioxide.
(i) Write an expression for the equilibrium constant, Kc, including the
units.
[2]
(ii) What does the position of the equilibrium indicate about the
magnitude of the equilibrium constant?
[1]
(f) Nitrogen dioxide is also produced when magnesium nitrate undergoes thermal decomposition.
2Mg(NO3)2(s) → 2MgO(s)  4NO2(g)  O2(g)
Calculate the atom economy of the above reaction.
[2]
42
Examiner Only
Marks Re-mark
THIS IS THE END OF THE QUESTION PAPER
43
BLANK PAGE
44
Centre Number
Candidate Number
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 3
Basic Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN PAPER
TIME
1 hour 15 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all three questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 25.
Figures in brackets printed down the right-hand side of pages
indicate the marks awarded to each question or part question.
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
1
2
3
Total
Marks
45
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
16
VI VII O
2
20
18
15
19
10
40
17
14
16
9
35.5
18
84
13
14
8
32
17
80
12
12
7
31
16
79
36
131
11
11
6
28
15
75
35
127
10
5
27
14
73
34
128
9
13
70
33
122
54
[222]
8
65
32
119
53
[210]
7
64
31
115
52
[209]
6
59
30
112
51
209
5
59
29
108
50
207
4
56
28
106
49
204
3
55
27
103
48
201
86
2
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
58
140
105
59
[231]
141
106
92
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
46
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
47
Safety glasses should be worn at all times and care should be exercised
during the Practical examination.
1
You are provided with a mixture P. It contains a soluble part and an
insoluble part.
(a) State its colour.
[1]
(b) How can you tell that there are two different substances in the
mixture?
[2]
(c) Heat a spatula measure of the mixture in a boiling tube.
(i) Describe what you see happening in the boiling tube. Refer to the
part which is heated, the middle of the boiling tube and the open
end of the boiling tube.
[2]
(ii) A liquid is formed, describe its appearance, and test its pH using
Universal Indicator solution.
[1]
(d) Place one spatula measure of the mixture onto a watch glass. Add
some dilute hydrochloric acid to the mixture.
(i) Describe what happens to the mixture.
[2]
48
Examiner Only
Marks Re-mark
(ii) Dip a piece of glass tubing into limewater and hold the glass
tubing over the mixture whilst it is reacting.
Examiner Only
Marks Re-mark
Describe what happens to the limewater.
glass tubing
limewater
watch glass
mixture
© CCEA
(e) Add 5 spatula measures of the mixture to 100 cm3 of warm water in a
beaker. Warm the mixture with stirring for about 5 minutes. Filter the
warm mixture into a conical flask.
[1]
Using a burette react 25 cm3 of the filtrate with 0.01 M hydrochloric
acid using phenolphthalein as the indicator. Repeat the procedure
using another 25 cm3 of the filtrate. Determine the volume of acid
needed to the nearest cm3.
(i) Explain what you would use to measure out 25 cm3 of the filtrate.
[2]
(ii) Complete the table below. Include any missing labels and write
the values observed in the reaction.
volume of acid at volume of acid at
the start/cm3
the end/cm3
rough value
value 1
value 2
[6]
(f) Carry out a flame test on the mixture using a piece of nichrome wire.
What colour is produced in the Bunsen flame?
49
[1]
[Turn over
2
You are supplied with three liquids X, Y and Z, in three separate test tubes.
One of them is ethanol.
(a) Add a very small piece of sodium to each liquid and observe what
happens. With each liquid state whether the sodium sinks or floats or
moves up and down. State whether a gas is given off. Place any
unreacted sodium, if any, back where it came from.
[3]
(b) Explain which liquid is ethanol.
[1]
50
Examiner Only
Marks Re-mark
3
Substance Q is a white organic solid. Heat the solid on a piece of broken
porcelain. Heat gently at first and then more strongly and then with a
roaring flame.
Examiner Only
Marks Re-mark
(a) Describe what happens to the white solid when it is heated. There
should be a minimum of three separate observations. The experiment
may be repeated if you wish.
[2]
(b) Explain which observation suggests that the solid is organic.
51
[1]
[Turn over
THIS IS THE END OF THE QUESTION PAPER
52
Centre Number
Candidate Number
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 3
Basic Practical Chemistry
Practical Booklet B
[CODE]
SPECIMEN PAPER
TIME
1 hour and 15 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all four questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 55.
Figures in brackets printed down the right-hand side of pages indicate
the marks awarded to each question or part question.
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
1
2
3
4
Total
Marks
53
1
I
II
THE PERIODIC TABLE OF ELEMENTS
Group
III
IV
15
V
16
VI VII O
2
20
18
14
19
10
40
17
13
16
9
35.5
18
84
12
14
8
32
17
80
11
12
7
31
16
79
36
131
10
11
6
28
15
75
35
127
9
5
27
14
73
34
128
8
13
70
33
122
54
[222]
7
65
32
119
53
[210]
6
64
31
115
52
[209]
5
59
30
112
51
209
4
59
29
108
50
207
3
56
28
106
49
204
2
55
27
103
48
201
86
1
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
58
140
105
59
[231]
141
106
92
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
54
General Information
Data Leaflet
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
55
1
The diagram below shows the reaction of sodium bromide or sodium
chloride with concentrated sulfuric acid.
Examiner Only
Marks Re-mark
water + universal indicator
sodium chloride/bromide
© CCEA
The gases produced in the reactions are passed through water which
contains Universal Indicator solution. The gases travel at a speed which is
proportional to their molecular masses.
(a) Describe what happens to the colour in the test tube when sodium
chloride is reacted.
[2]
(b) Describe what happens to the colour in the test tube when sodium
bromide is reacted.
[2]
56
2
A student is provided with a mixture of potassium carbonate and barium
carbonate.
Describe how you would separate the two substances and show that
barium carbonate was present.
Examiner Only
Marks Re-mark
57
[4]
[Turn over
3
1-chlorobutane may be prepared as follows:
Examiner Only
•
Fit a 250 cm3 round-bottomed flask with a reflux condenser, the top of
which is connected to apparatus for absorbing hydrogen chloride.
•
Place 68 g (0.5 mol) of anhydrous zinc chloride and 40 cm3 of
concentrated hydrochloric acid in the flask.
•
Add 23 cm3 of butan-1-ol and gently reflux the mixture for 2 hours.
•
Arrange the condenser for distillation and distil the mixture collecting
the liquid which boils below 115 °C.
•
Separate the upper layer of the distillate, mix it with an equal volume
of concentrated sulfuric acid and transfer the mixture to a flask fitted
with a reflux condenser.
•
Reflux gently for 15–30 minutes and then distil the 1-chlorobutane
from the acid at 76–79 °C.
•
Wash the distillate successively with 25 cm3 of water, 10 cm3 of 1M
sodium hydroxide solution and 25 cm3 of water.
•
Leave the 1-chlorobutane over 2 g of anhydrous calcium chloride and
distil from a small distillation flask.
•
The 1-chlorobutane is collected at 75–78 °C.
(a) Draw a labelled diagram of apparatus which can absorb hydrogen
chloride gas and explain how it works.
[3]
(b) Suggest the purpose of the anhydrous zinc chloride in the preparation
of 1-chlorobutane.
[1]
58
Marks Re-mark
(c) The mixture is gently refluxed.
Examiner Only
Marks Re-mark
Explain the difference that you would observe between gentle and
vigorous refluxing.
(d) Concentrated sulfuric acid is used to remove impurities which are not
easily separated by distillation.
Suggest why these impurities are difficult to remove.
[1]
(e) The upper layer of the distillate is separated.
Suggest the name of the substance that forms the lower layer.
[1]
[1]
(f) The distillate is washed with water and sodium hydroxide solution.
Explain, giving full experimental detail, how this washing is carried
out.
[4]
(g) Explain the use of the anhydrous calcium chloride and name an
alternative substance that could be used.
59
[2]
[Turn over
(h) Use the following method to calculate the mass of 1-chlorobutane
obtained in the preparation.
Examiner Only
Marks Re-mark
(i) The density of butan-1-ol is 0.81.
State the units for density and use this information to calculate
the mass of 23 cm3 of butan-1-ol.
[2]
(ii) Calculate the yield of 1-chlorobutane from this mass of butan-1-ol
assuming the hydrochloric acid is in excess.
[2]
(i) The purity of the 1-chlorobutane may be judged from its boiling point.
A student stated that the boiling point was 78.4 °C and a chemical data
book quoted 77–78 °C.
Comment on these values and state why the 1-chlorobutane was
collected at 75–78 °C.
[3]
(j) The infrared spectrum of the prepared 1-chlorobutane is a good
indication of its purity.
Suggest how you could use the infrared spectrum to determine
whether the 1-chlorobutane is 100% pure.
[2]
60
4
The trends in the reaction of the Group II metals with steam can be
investigated using the apparatus below.
Examiner Only
Marks Re-mark
M
steam
burette
heat
trough
water
© CCEA
The steam is passed over the heated metal and then into a container of
water and the hydrogen produced is collected and measured.
(a) Write the equation, including state symbols, for the reaction of a
Group II metal, M, with steam.
[2]
(b) In order for a valid comparison to be made the metals should be the
“same”.
What three things would you do to ensure that the metals are the
“same”?
[3]
(c) It might seem surprising that steam at a temperature of 100 °C is used
rather than water at 25 °C.
(i) Suggest why it is safer to use steam rather than water.
[1]
(ii)State three observations for the reaction of calcium with water at
25 °C in a gas jar.
61
[3]
[Turn over
(d) The rate of hydrogen production is an indication of the rate of
reactivity of the metal with steam. The graph below shows the result
for magnesium.
(i) Label the axes on the graph including the units.
[2]
(ii) Draw on the graph the expected result for calcium.
[2]
(iii) Describe how you would obtain a sample of gas from the burette
and use a chemical test to show that the gas was hydrogen.
[3]
(e) Calculate the volume of hydrogen collected from 3.40 g of calcium
reacting with steam at 20°C and one atmosphere pressure.
Give your result to two significant figures.
[4]
62
Examiner Only
Marks Re-mark
(f) A student suggested using similar apparatus to measure the trends in
reaction of the Group II metals with oxygen.
Examiner Only
Marks Re-mark
Explain the difficulties that this method would pose and how they
could possibly be overcome.
[5]
63
10229.05
[Turn over
THIS IS THE END OF THE QUESTION PAPER
64
Centre Number
Candidate Number
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 1
Further Physical and Organic Chemistry
[CODE]
SPECIMEN PAPER
TIME
2 hours
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the
spaces
provided at the top of this page.
Write your answers in the spaces provided in this question
paper.
Answer all seventeen questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 110.
Figures in brackets printed down the right-hand side of pages
indicate the marks awarded to each question or part question.
Quality of written communication will be assessed in
Questions 13(c)(ii) and 17(b)(iii).
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
Section A
 1–10
Section B
11
12
13
14
15
16
17
Total
Marks
65
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
16
VI VII O
2
20
18
15
19
10
40
17
14
16
9
35.5
18
84
13
14
8
32
17
80
12
12
7
31
16
79
36
131
11
11
6
28
15
75
35
127
10
5
27
14
73
34
128
9
13
70
33
122
54
[222]
8
65
32
119
53
[210]
7
64
31
115
52
[209]
6
59
30
112
51
209
5
59
29
108
50
207
4
56
28
106
49
204
3
55
27
103
48
201
86
2
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
58
140
105
59
[231]
141
106
92
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
66
Data Leaflet
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
67
Section A – Multiple Choice
Select the correct response in each case and mark its code letter by
connecting the dots as illustrated on the answer sheet.
Each Multiple Choice question is worth 1 mark.
1
Propanone reacts with iodine in the presence of an acid according to the equation:
CH3COCH3(aq)  I2(aq) → CH3COCH2I(aq)  HI(aq)
The most appropriate method for investigating the rate of this reaction is
A titrating samples with an acid
B titrating samples with sodium thiosulfate
C using a graduated syringe
D weighing the reaction vessel
2
Heat is produced when magnesium reacts with sulfuric acid:
Mg(s)  H2SO4(aq) → MgSO4(aq)  H2(g)
Which one of the following is true for the reaction?
A ∆S is negative
B ∆H is positive
C ∆G is positive
D the reaction is feasible at any temperature
3
One mole of propanoic acid, one mole of methanol and two moles of water were mixed and
allowed to reach equilibrium. At equilibrium 0.5 mole of methyl propanoate was present.
The value of Kc for this reaction is
A1.00
B1.25
C5.00
D10.00
68
4
Which one of the following graphs shows a reaction that is first order with respect to
reactant Z?
Rate
Rate
[Z]
[Z]
B
A
[Z]
Time
Time
[Z]
C
D
© CCEA
5
Which one of the following represents the units of Kc for the equilibrium shown below?
N2(g)  3H2(g)
Amol–2 dm–6
Bmol–2 dm6
Cmol2 dm–6
Dmol2 dm6
69
2NH3(g)
6
Which one of the following is the systematic name for the carboxylic acid shown below?
CH3 H
H
CH3
H—C—C—C—C—C
H
H
H
H
O
OH
A
1,4-dimethylpentanoic acid
B 2,5-dimethylpentanoic acid
C 2-methylhexanoic acid
D 5-methylhexanoic acid
7
Which one of the following compounds reacts with both LiAIH4 and PCI5?
ACH3CH2OH
BCH3CH2CHO
CCH3COCH3
DCH3CH2COOH
8
Which one of the following statements about the formation of an ester from ethanoyl
chloride and propan-1-ol is correct?
A
B Heat is required
C The ester produced is called ethyl propanoate
D The reaction goes to completion
9
Butan-1-ol was reacted with an excess of propanoic acid in the presence of a small amount
of concentrated sulfuric acid. 6.0 g of the alcohol produced 7.4 g of the ester. Which one of
the following is the percentage yield of the ester?
Concentrated sulfuric acid is required
A57%
B70%
C75%
D81%
70
10 Which one of the following salts will dissolve to produce a solution with the highest pH?
A Ammonium chloride
B Ammonium ethanoate
C Sodium chloride
D Sodium ethanoate
71
Section B
Examiner Only
Marks Re-mark
Answer all seven questions in this section.
11 Data for the reduction of iron(lll) oxide by carbon, are shown in the table
below.
2Fe2O3(s)  3C(s) → 4Fe(s)  3CO2(g)
substance
∆fH⦵/kJ mol–1
S⦵/J K–1 mol–1
Fe2O3
–824.2
87.4
C
0.0
5.7
Fe
0.0
27.3
CO2
–393.5
213.6
(a) (i) Calculate the values of ∆H⦵, ∆S⦵ and ∆G⦵ for the reaction at
298 K.
∆H⦵ [2]
∆S⦵ [2]
∆G⦵ [1]
(ii) Using your results from part (i) explain why this reaction is not
feasible at 298 K.
[1]
72
(b) Calculate the temperature above which this reaction is feasible.
Examiner Only
Marks Re-mark
73
[2]
[Turn over
12 The strength of the ionic bonding in compounds, such as magnesium
fluoride and magnesium chloride, is related to the lattice enthalpy of the
compound.
Examiner Only
Marks Re-mark
(a) Define the term lattice enthalpy.
[2]
(b) (i) Complete the Born-Haber cycle for magnesium fluoride:
Mg2(g)  2e–  2F(g)
Mg2(g)  2e–  F2(g)
Mg(g)  F2(g)
[4]
74
(ii) Using the data given below, calculate the lattice enthalpy for
magnesium fluoride.
Standard enthalpy of formation for magnesium fluoride
First electron affinity of fluorine
Atomisation enthalpy of fluorine
First ionisation enthalpy of magnesium
Second ionisation enthalpy of magnesium
Atomisation enthalpy of magnesium
Examiner Only
Marks Re-mark
kJ mol–1
–1123
–348
79
736
1450
150
(c) Magnesium fluoride and magnesium chloride are both soluble in
water. Magnesium chloride has an enthalpy of solution of
–155 kJ mol–1.
[2]
(i) Using diagrams, show how magnesium and fluoride ions interact
with water molecules in an aqueous solution of magnesium
fluoride.
[2]
(ii) Given that the enthalpies of hydration of magnesium ions and
chloride ions are –1920 kJ mol–1 and –364 kJ mol–1 respectively,
calculate the lattice enthalpy of magnesium chloride.
75
[2]
[Turn over
13 Butanone reacts with hydrogen cyanide to form a product that contains an
asymmetric centre.
OH
CH3CH2 — C — CN
CH3
The reaction mechanism is similar to that for the reaction between
hydrogen cyanide and propanone.
(a) (i) Give the systematic name of the product.
[2]
(ii) What type of stereoisomerism is shown by the product?
[1]
(iii) Draw the 3D representations of the stereoisomers.
[2]
(iv) Name the mechanism for the reaction.
[1]
(v) Draw the mechanism for this reaction.
76
[4]
Examiner Only
Marks Re-mark
(vi) Explain, in terms of the mechanism, why a racemic mixture is
produced in this reaction.
Examiner Only
Marks Re-mark
[3]
(b) Butanal is a structural isomer of butanone.
Describe, giving practical details, how you would carry out a chemical
test to distinguish between samples of butanal and butanone.
77
[3]
[Turn over
(c) 2,4-dinitrophenylhydrazine reacts with both butanone and butanal to
form 2,4-dinitrophenylhydrazones.
(i) Write the equation for the reaction of butanone with
2,4-dinitrophenylhydrazine.
[2]
(ii) Describe what is observed in these reactions and explain,
experimentally, how the 2,4-dinitrophenylhydrazones can be used
to confirm the identity of the reactant.
In this question you will be assessed on using your written
communication skills including the use of specialist
scientific terms.
[6]
78
Examiner Only
Marks Re-mark
14 At 25°C, the acid dissociation constant, Ka, for propanoic acid
CH3CH2COOH, is 1.35  10–5 mol dm–3. A buffer solution can be
prepared by mixing a solution of propanoic acid with a solution of sodium
propanoate.
Examiner Only
Marks Re-mark
(a) (i) Write the expression for the acid dissociation constant of
propanoic acid.
[1]
(ii) Calculate the pH of a 0.25 mol dm–3 solution of propanoic acid.
[3]
(iii) What is meant by the term buffer solution?
[2]
(iv) Calculate the pH of the buffer solution formed when 300 cm3 of
a 0.25 mol dm–3 solution of propanoic acid is mixed with 200 cm3
of a 0.15 mol dm–3 solution of sodium propanoate.
79
[4]
[Turn over
(b) The titration curve below shows the change in pH when a 0.20 mol dm–3 solution of sodium hydroxide is added, from a burette, to 25.0 cm3 of a solution of propanoic acid of unknown concentration.
pH
18.5
Volume of NaOH added (cm3)
© CCEA
(i) Write the equation for the neutralisation reaction which occurs.
[1]
(ii) Suggest a suitable indicator for this titration. Give the colour
change and explain why the indicator is suitable.
[4]
(iii) Calculate the concentration of the propanoic acid.
[3]
80
Examiner Only
Marks Re-mark
(iv) At 25 °C, Kw has the value 1.00  10–14 mol2 dm–6.
Examiner Only
Marks Re-mark
Calculate the pH of the 0.20 mol dm–3 solution of sodium
hydroxide.
81
[2]
[Turn over
15 Benzene is toxic and carcinogenic, however, the reactions of aromatic
compounds can be studied in the laboratory using other substances such
as methyl benzoate.
(a) The electrons in the π bonds in benzene are delocalised.
Draw two structures for benzene to show the p-orbitals before and
after delocalisation.
before
after
[2]
(b) Nitration of methyl benzoate can be achieved using a "nitrating
mixture" of concentrated nitric and sulfuric acids.
(i) Write an equation to show how these two acids react when mixed.
[2]
(ii) Name the ion, produced in this reaction, which attacks the methyl
benzoate molecule.
[1]
82
Examiner Only
Marks Re-mark
(iii) Draw the mechanism of the mononitration of methyl benzoate and
name the mechanism.
[5]
(iv) Name the organic product of this reaction.
Examiner Only
Marks Re-mark
[1]
(v) Describe the appearance of this organic product.
[1]
83
[Turn over
16 The ionic equation for the alkaline hydrolysis of C4H9Br is shown below.
C4H9Br  OH– → C4H9OH  Br –
Data for this reaction is given in the table below.
experiment
initial
[C4H9Br]
(mol dm–3)
initial
[OH–]
(mol dm–3)
initial rate
(mol dm–3s–1)
1
0.02
0.02
40.0
2
0.01
0.02
20.0
3
0.03
0.04
60.0
(a) What is the order of the reaction with respect to C4H9Br?
Explain your reasoning.
[2]
(b) What is the order with respect to OH–? Explain your reasoning.
[2]
(c) Write the rate equation for the reaction.
[1]
(d) Calculate a value for the rate constant and give its units.
[2]
84
Examiner Only
Marks Re-mark
(e) Draw a reaction mechanism for the hydrolysis of C4H9Br which is
consistent with your rate equation. Show the structure of C4H9Br
clearly in your mechanism and identify the rate determining step.
85
Examiner Only
Marks Re-mark
[5]
[Turn over
17 Fats and vegetable oils are triesters of long-chain carboxylic acids. Base
catalysed hydrolysis of an oil produces glycerol and the sodium salt of
octadeca-9,12-dienoic acid as the only products.
CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH
octadeca-9,12-dienoic acid
(a) (i) Draw the structure of glycerol.
[1]
(ii) State the systematic name for glycerol.
[1]
(iii) Draw the structure of the oil.
[1]
86
Examiner Only
Marks Re-mark
(b) Simple monoesters, such as the one shown below, can be prepared
by reacting carboxylic acids with alcohols:
CH3 H
O
H—C—C—C
CH3 H
O— CH3
(i) Give the systematic names of the carboxylic acid and alcohol
required to prepare this ester.
Acid Alcohol [1]
(ii) Write the equation for the formation of the ester.
[2]
(iii) Describe, giving experimental details, the preparation of a pure,
dry sample of the ester.
In this question you will be assessed on using your written
communication skills including the use of specialist
scientific terms.
87
[6]
Examiner Only
Marks Re-mark
THIS IS THE END OF THE QUESTION PAPER
88
Centre Number
Candidate Number
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 2
Analytical, Transition Metals, Electrochemistry
and Organic Nitrogen Chemistry
[CODE]
SPECIMEN PAPER
TIME
2 hours.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all seventeen questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 110.
Figures in brackets printed down the right-hand side of pages
indicate the marks awarded to each question or part question.
Quality of written communication will be assessed in Questions
16(b)(ii) and 17(c).
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
Section A
 1–10
Section B
11
12
13
14
15
16
17
Total
Marks
89
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
VI VII O
2
20
18
16
19
10
40
11
16
9
35.5
18
84
10
14
8
32
17
80
8
12
7
31
16
79
36
131
3
11
6
28
15
75
35
127
2
5
27
14
73
34
128
4
15
13
70
33
122
54
[222]
17
14
65
32
119
53
[210]
13
64
31
115
52
[209]
12
59
30
112
51
209
9
59
29
108
50
207
7
56
28
106
49
204
6
55
27
103
48
201
86
5
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
140
105
59
[231]
141
106
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
58
92
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
90
Data Leaflet
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
91
Section A – Multiple Choice
Select the correct response in each case and mark its code letter by connecting the dots
as illustrated on the answer sheet.
Each Multiple Choice question is worth 1 mark.
1
Which organic compound gives rise to the largest number of peaks in an nmr spectrum?
ACH3CH2COCH2CH3
BCH3COOH
CCH3CH2Br
DCH3CH2COOCH3
2
Which is correct for a lithium ion battery?
A
B Lithium ions move from the positive electrode to the negative electrode during
discharge
C The battery can be used safely at high temperature
D The electrolyte is an aqueous solution of a lithium salt
3
Which statement describes the primary structure of a protein?
A
B The folding of a beta-pleated sheet
C The sequence of amino acids
D The coiling of the chains
4
Which one of the following describes the charge and coordination number of nickel in the
[Ni(edta)]2– complex?
Lithium ions move from the negative electrode to the positive electrode during
discharge
The folding of an alpha-helix
charge
coordination number
A 2
1
B 2–
4
C 26
D 2–
8
92
5
Which one of the following ions is not present in a coloured compound?
A[Cu(NH3)4(H2O)2]2
B[Fe(SCN)(H2O)5]2
C[Ni(NH3)4(H2O)2]2
D[Zn(NH3)4(H2O)2]2
6
The standard electrode potentials for a series of redox equations are listed below.
E /V
Mn2(aq)  2e–
Mn(s)
–1.19
Fe2(aq)  2e–
Fe(s)
–0.44
Ni2(aq)  2e–
Ni(s)
–0.25
I2(s)  2e–
Fe3(aq)  e–
2I–(aq)
0.54
Fe2(aq)
0.77
Ag(s)
0.80
Ag(aq)  e–
Which element will reduce Fe3(aq) to Fe2(aq) but not to Fe(s)?
AIodine
BManganese
CNickel
DSilver
7
Which one of the following pairs of monomers will not combine to form a polymer?
AHOOC(CH2)4COOH and H2N(CH2)6NH2
BH2N(CH2)6NH2 and H2N(CH2)6NH2
CCH2CH2 and CH2CH2
DHOOC(CH2)4COOH and HO(CH2)2OH
93
8
In the complex ion [MCl2(NH3)4], what is the oxidation number of M?
A
1
B
2
C
3
D
7
9
Iodoethane may be converted to propylamine by reaction with
Aammonia
B ammonia followed by LiAlH4
C potassium cyanide followed by ammonia
D potassium cyanide followed by LiAlH4
10 In a solution at pH 1 glycine exists as
Aanions
Bcations
C dipolar ions
D neutral molecules
94
Section B
Examiner Only
Marks Re-mark
Answer all seven questions in this section.
11 The USA space programme supported research to develop fuel cells. The
Shuttle missions used a fuel cell based on the reaction of hydrogen and
oxygen in an alkaline medium to form water.
(a) Write equations to represent the electrode reactions in an alkaline
hydrogen fuel cell.
Anode [1]
Cathode [1]
(b) Write an equation, including state symbols, for the overall reaction in
the hydrogen-oxygen fuel cell.
[2]
(c)State two advantages of a hydrogen-oxygen fuel cell.
95
[2]
[Turn over
12 Proteins are synthesised from 20 essential amino acids. Recent research
has shown that some organisms also use another amino acid called
selenocysteine, which is shown below.
CH3
H2N — C — COOH
CH2SeH
(a) Explain why selenocysteine, like other amino acids, would be
expected to have a high melting point.
[2]
(b) Selenocysteine reacts with sodium carbonate solution.
Write an equation for this reaction.
[2]
(c)Some E.coli bacteria contain selenoproteins which are enzymes.
(i) Draw the structure of the dimer formed between two
selenocysteine molecules and circle the peptide link.
[3]
96
Examiner Only
Marks Re-mark
(ii) Explain the mechanism by which the enzyme works.
Examiner Only
Marks Re-mark
[1]
(iii) Draw a graph, labelling the axes, to show how the enzyme activity
is affected by altering the pH.
97
[2]
[Turn over
13 The determination of iron in its ores is an example of the application of
manganate(VII) titrations. Before titration with manganate(VII) ions any
iron(III) must be reduced to iron(II). This reduction can be carried out with
zinc amalgam (a mixture of zinc and mercury).
Zn2(aq)  2e–
Zn(s)
E  –0.76 V
Fe2(aq)  2e–
Fe(s)
E  –0.44 V
Fe3(aq)  e–
Fe2(aq)
E  +0.77 V
(a)(i) Write the equation for the reaction between zinc and iron(III) ions.
[1]
(ii) The use of zinc amalgam prevents the further reduction of iron(II)
to iron.
Use the electrode potentials above to explain why, in theory, zinc
would also reduce iron(II) to iron.
[1]
(b) Potassium manganate(VII) is used to determine the concentration of
iron(II) in solution. The half-equations are:
MnO4–  8H  5e– → Mn2  4H2O
Fe2 → Fe3  e–
(i) Write an ionic equation for the reaction of acidified manganate
(VII) with iron(II) ions.
[1]
98
Examiner Only
Marks Re-mark
(ii) A sample of steel with a mass of 1.60 g was dissolved in an
excess of dilute sulfuric acid and the solution made up to 250 cm3
with water. Several 25.0 cm3 samples of this solution, containing
the iron(II) ions, were titrated with 0.02 mol dm–3 potassium
manganate(VII) solution. The average titre was 26.0 cm3.
Examiner Only
Marks Re-mark
Calculate the percentage of iron in the sample of steel.
[4]
(iii) What is the colour change at the end point?
99
[2]
[Turn over
14 Amines may be prepared by the reduction of nitriles or by the reaction of
ammonia with haloalkanes.
(a) 1-bromobutane reacts with ammonia (by a similar mechanism to that
of the alkaline hydrolysis of haloalkanes) to form 1-aminobutane.
(i) Name the mechanism.
[1]
(ii) Write an equation for the reaction.
[1]
(iii) Without using a flow scheme suggest an explanation for the mechanism for the reaction.
[3]
(b) 1-aminobutane may also be prepared by the reduction of butanenitrile.
(i) Name a suitable reducing agent.
[1]
(ii) Using [H] to represent the reducing agent write an equation for
the reduction of butanenitrile.
[2]
(c) Phenylamine (aniline) was discovered in 1826 by distilling the dye indigo. The name aniline is derived from anil, the
Portuguese word for indigo. Reduction of nitrobenzene produces
aniline.
Write the equation for the reduction of nitrobenzene using [H] to
represent the reducing agent.
100
[2]
Examiner Only
Marks Re-mark
(d) Aniline is basic and reacts with strong acids to form crystalline salts.
Examiner Only
Marks Re-mark
(i) State the basicity of aniline compared to ammonia and
phenylethylamine, C6H5CH2CH2NH2.
[1]
(ii) Write the equation for the reaction of aniline with hydrochloric
acid.
[1]
(iii) Explain why phenylethylamine is a primary amine.
[1]
(e) When aniline is treated with nitrous acid at a low temperature the
benzenediazonium ion is formed.
(i)
Draw the structure of the benzenediazonium ion, C6H5N2,
showing all the bonds between the nitrogen atoms and the
location of the charge. Do not show the detailed structure of the
benzene ring.
[2]
(ii) Name the reagents used to generate the nitrous acid.
101
[1]
[Turn over
(iii) If a solution of benzenediazonium ion is treated with aqueous
sodium cyanide in the presence of a copper catalyst,
cyanobenzene is formed.
Name the reagents A – D in the following flow scheme.
C6H5N2
NaCN/Cu
→
C6H5CN
C6H5COOH
C
→
D
C6H5CH2OH → C6H5CH2Cl
→
B
A
→
C6H5CH2NH2
A
_____________________________
B _____________________________
C
_____________________________
D
_____________________________[4]
102
Examiner Only
Marks Re-mark
15 Transition metal chemistry is characterised by catalytic activity, redox
reactions, colour changes and ligand replacement. Vanadium and
chromium are typical transition metals.
Examiner Only
Marks Re-mark
(a) Explain, in terms of electronic structure, why vanadium and chromium
are transition metals.
[1]
(b) An acidified solution of ammonium vanadate(V) undergoes a series of
reductions when it is stirred with zinc.
(i) Complete the table below giving the colour of VO2(aq) and
V3(aq) formed at the different stages of the reduction.
ion
colour
VO2
Yellow
VO2(aq)
V3(aq)
V2(aq)
Violet
[2]
(ii) Chromium will also reduce ammonium vanadate(V).
E /V
Cr3(aq)  3e–
VO2(aq)  2H(aq)  e–
Write an equation for the reaction between chromium and
VO2(aq) ions and calculate the e.m.f. of the reaction.
Cr(s) –0.74
VO2(aq)  H2O(l)
1.00
103
[3]
[Turn over
(c) The colour of a transition metal complex depends upon its
coordination number and the ligands attached to the metal ion.
This is illustrated by the following:
[Cu(H2O)6]2(aq)  4Cl–(aq)
Examiner Only
Marks Re-mark
[CuCl4]2–(aq)  6H2O(l)
(i) State the colours of the two copper complexes.
[Cu(H2O)6]2(aq) ________________________________
[CuCl4]2–(aq) ________________________________[2]
(ii) State the shape of the hexaaquacopper(II) ion.
[1]
(iii) Name a suitable reagent which could be added to the equilibrium
to shift it to the right.
[1]
(d) 1,2-diaminoethane is a bidentate ligand which complexes with
aqueous nickel(II) ions.
(i) Draw the structure of 1,2-diaminoethane.
[1]
(ii) What is meant by the term bidentate?
[1]
104
(iii) State the formula of the complex formed when excess
1,2-diaminoethane (represented as ‘en’) is added to aqueous
nickel(II) ions.
Examiner Only
Marks Re-mark
[2]
(e) Trinitrotriammine cobalt(III), [Co(NO2)3(NH3)3], is a yellow crystalline
substance which may be prepared by the following method.
Dissolve 12.2 g of cobalt(II) ethanoate tetrahydrate in 100 cm3 of hot
water. Cool the solution in an ice bath and add 10.4 g of sodium nitrite
dissolved in 50 cm3 of “0.88” ammonia. Cool to 10 °C and carefully
add 14 cm3 of 20 volume hydrogen peroxide solution followed by 2 g
of activated charcoal. After stirring, the mixture is left for 10 minutes
before boiling for 30 minutes. Filter the hot solution to remove the
activated charcoal and cool the filtrate in an ice bath. Filter off the
crystals, wash with cold ethanol and dry.
(i) Deduce the formula of cobalt(II) ethanoate tetrahydrate.
[2]
(ii) State and explain the role of hydrogen peroxide in this
preparation.
[2]
(iii) Suggest the shape of the trinitrotriammine cobalt(III) complex.
[1]
(iv) Deduce the coordination number of cobalt in the trinitrotriammine
cobalt(III) complex.
105
[1]
[Turn over
(v) 20 volume hydrogen peroxide is so named because 1 cm3 of the solution produces 20 cm3 of gaseous oxygen on complete decomposition at 20 °C and one atmosphere pressure.
2H2O2(aq) → 2H2O(l)  O2(g)
Calculate the concentration of 20 volume hydrogen peroxide in
mol dm–3.
[3]
106
Examiner Only
Marks Re-mark
16 Propanoic acid and ethyl methanoate are isomers which can be identified
using spectroscopic techniques.
Examiner Only
Marks Re-mark
(a) (i) Explain why propanoic acid and ethyl methanoate are regarded
as isomers.
[2]
(ii) Write the equation for the formation of ethyl methanoate by an
esterification reaction with ethanol.
[2]
(iii) The esterification is an equilibrium reaction.
Explain how you would increase the yield of ethyl methanoate.
[2]
(b) The nmr spectrum of ethyl methanoate is shown below.
© CCEA
(i)Name the substance responsible for the signal at 0 and state its
formula.
107
[2]
[Turn over
(ii) Explain the nmr spectrum of ethyl methanoate with reference to
spin-spin splitting, peak integration and chemical shift.
Examiner Only
Marks Re-mark
In this question you will be assessed on using your written
communication skills including the use of specialist
scientific terms.
[6]
108
(c) The mass spectrum of ethyl methanoate is shown below.
Examiner Only
Marks Re-mark
100
31
28
80
60
relative
abundance
40
45
20
74
0
20
30
40
50
60
70
80
m/e
© CCEA
Identify the ions responsible for the peaks.
m/e
ion
28
_________________________
45
_________________________ [2]
(d) (i) Explain how the absorption of radiation by molecules gives rise to
infrared spectra and how you would use infrared spectroscopy to
distinguish between propanoic acid and ethyl methanoate.
[4]
(ii) How would you distinguish between propanoic acid and ethyl
methanoate using a chemical test?
[2]
109
10229.03
[Turn over
17
For a long time the bark of the willow tree (salix alba) was used to relieve
fever symptoms. The active ingredient is salicylic acid but it has some
undesirable side effects. In 1899 the ethanoate ester of salicylic acid was
found to reduce these side effects. It was given the trade name Aspirin.
(a) Aspirin is prepared by reacting ethanoic anhydride, C4H6O3, with
2-hydroxybenzoic acid.
Using molecular formulae write an equation for this reaction.
[2]
(b) What property of Aspirin allows the crude Aspirin formed in this reaction to
be washed with chilled water as part of the purification process?
[1]
(c) Describe, giving full experimental detail, the TLC method which can be
used to investigate the purification process. The developing solvent is
ethyl ethanoate.
In this question you will be assessed on using your written
communication skills including the use of specialist scientific terms.
[6]
(d) Suggest why TLC is preferable to GLC for this preparation.
[1]
110
Examiner Only
Marks Re-mark
THIS IS THE END OF THE QUESTION PAPER
111
BLANK PAGE
112
Centre Number
Candidate Number
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 3
Further Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN PAPER
TIME
1 hour 15 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all five questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 30.
Figures in brackets printed down the right-hand side of pages
indicate the marks awarded to each question or part question.
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
 1
 2
 3
 4
 5
Total
Marks
113
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III
IV
V
16
VI VII O
19
10
40
2
20
18
15
16
9
35.5
18
84
4
14
14
8
32
17
80
17
13
12
7
31
16
79
36
131
12
11
6
28
15
75
35
127
11
5
27
14
73
34
128
10
13
70
33
122
54
[222]
9
65
32
119
53
[210]
8
64
31
115
52
[209]
7
59
30
112
51
209
6
59
29
108
50
207
5
56
28
106
49
204
4
55
27
103
48
201
86
3
52
26
101
47
197
85
2
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
140
105
59
[231]
141
106
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
58
92
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
114
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
115
Safety glasses should be worn at all times and care should be exercised
during practical examinations.
1
You are required to titrate standard potassium manganate(VII) solution
against sodium ethandioate.
5Na2C2O4  2KMnO4  8H2SO4 → K2SO4  2MnSO4  10CO2  8H2O  5Na2 SO4
You are provided with:
•
•
•
You should:
1 Rinse out and fill the burette with the potassium manganate(VII)
solution
2 Using a pipette add 25 cm3 of the sodium ethandioate solution to a
conical flask
3 Add a portion of sulfuric acid to the conical flask
4 Warm the conical flask to slightly above room temperature
5 Titrate the potassium manganate(VII) solution against the sodium
ethandioate solution
a solution of sodium ethanedioate
four 20 cm3 portions of sulfuric acid
potassium manganate(VII) solution of concentration 0.20 mol dm–3
(a) Complete the following results table.
burette reading
at the start/cm3
burette reading
at the end/cm3
volume of
potassium
manganate(VII)
added/cm3
rough titration
accurate titration
accurate titration
Average titration value  __________________________
[6]
(b) Explain how you would read the value of the volume of potassium
manganate(VII) in the burette.
[2]
(c) What is the colour change in the conical flask?
[2]
116
Examiner Only
Marks Re-mark
2
The solid provided is an iron compound.
Carry out the following tests to determine which iron compound it is.
Write what is observed in each case.
(a) Describe the appearance of the solid.
Examiner Only
Marks Re-mark
(b) Dissolve the solid in water and state the colour of the solution.
[1]
(f) Add silver nitrate solution to part of the solution.
[1]
(e) Add barium chloride solution to part of the solution.
[1]
(d) Add dilute ammonia solution to part of the solution.
[1]
(c) Add sodium hydroxide solution to part of the solution.
[1]
[1]
(g) Name the iron compound.
117
[1]
[Turn over
3
The depth of colour of a solution can be used to determine the formula of a
coloured complex. In order to do this, solutions of various depths of
colour, in test tubes, are compared with that of a standard solution. The
reverse can be carried out. A concentrated solution of a coloured
compound can be successively diluted until the depth of its colour matches
that of a known solution.
(a) You are provided with a concentrated solution X of copper(II) sulfate of
known concentration 5M and a solution of unknown concentration Y.
Dilute the solution X until it has the same colour as that of solution Y.
Explain your “dilutions” by stating the volumes and apparatus used
and how you compared the colour of the known solution with that of
the unknown solution.
[4]
(b) What is the concentration of the unknown solution?
[1]
118
Examiner Only
Marks Re-mark
4
Z is an organic substance. Dissolve a couple of crystals of Z in an ignition
tube a third filled with propanone. Dip a capillary tube into the liquid and
place a spot of the solution onto a TLC plate. Let the propanone
evaporate. Cut the TLC plate to fit a 250 cm3 beaker and place it in the
beaker which contains ethanol and has a lid. Allow the ethanol to run to
near the top of the TLC plate. Remove the TLC plate, leave for a couple
of minutes and place in a container of iodine which is in a fume cupboard.
(a) Draw a sketch of the result after placing the TLC plate in iodine. Label
the solvent front and the starting point.
Examiner Only
Marks Re-mark
[3]
(b) How many substances are there in Z?
119
[1]
[Turn over
5
Solutions L1, L2 and L3 contain three different ligands. One of them is
monodentate and the others are bidentate and polydentate. All of them
form complexes with copper(II) ions.
Examiner Only
Marks Re-mark
Complete the following table which shows a “competition” between the
ligands. Each box in the table should have a description of the change of
colour or lack of change of colour which takes place when the solutions
are mixed. The greater number of reactions will lead to the ligand with the
greatest denticity.
Ligand 1
Ligand 2
Ligand 3
Copper(II) complex
with ligand 1
Copper(II) complex
with ligand 2
Copper(II) complex
with ligand 3
[4]
120
THIS IS THE END OF THE QUESTION PAPER
121
BLANK PAGE
122
Centre Number
Candidate Number
General Certificate of Education
2018
Chemistry
Assessment Unit A2 3
Further Practical Chemistry
Practical Booklet B
[CODE]
SPECIMEN PAPER
TIME
1 hour 15 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces
provided at the top of this page.
Write your answers in the spaces provided in this question paper.
Answer all four questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 60.
Figures in brackets printed down the right-hand side of pages
indicate the marks awarded to each question or part question.
A Data Leaflet including a Periodic Table of the Elements is included
with this question paper.
For Examiner’s
use only
Question
Marks
Number
 1
 2
 3
 4
Total
Marks
123
1
I
1
II
THE PERIODIC TABLE OF ELEMENTS
Group
III IV
V
16
VI VII O
2
20
18
15
19
10
40
17
14
16
9
35.5
18
84
13
14
8
32
17
80
12
12
7
31
16
79
36
131
11
11
6
28
15
75
35
127
10
5
27
14
73
34
128
9
13
70
33
122
54
[222]
8
65
32
119
53
[210]
7
64
31
115
52
[209]
6
59
30
112
51
209
5
59
29
108
50
207
4
56
28
106
49
204
3
55
27
103
48
201
86
2
52
26
101
47
197
85
4
9
51
25
[98]
46
195
84
7
1
4
24
48
24
96
45
192
83
3
23
45
23
93
44
190
82
12
40
22
91
43
186
81
11
39
21
89
42
184
80
20
88
41
181
79
[272]
19
85
40
178
78
[271]
*
77
[268]
39
139
76
[277]
38
137
75
[264]
37
133
74
[266]
58
140
105
59
[231]
141
106
92
60
238
144
107
93
61
[237]
145
108
94
62
[242]
150
109
95
63
[243]
152
110
96
64
[247]
157
111
97
65
[245]
159
98
66
[251]
162
99
67
[254]
165
100
68
[253]
167
101
69
[256]
169
102
70
[254]
173
103
71
[257]
175
Elements with atomic numbers 112-116 have been
reported but not fully authenticated
73
[262]
†
104
72
[261]
57
[227]
89
56
[226]
88
55
[223]
87
* 58 – 71 Lanthanum series
† 90 – 103 Actinium series
a
x
b
91
90
a = relative atomic mass (approx) 232
x = atomic symbol
b = atomic number
124
Data Leaflet
General Information
1 tonne = 106 g
1 metre = 109 nm
One mole of any gas at 293K and a pressure of 1 atmosphere (105 Pa) occupies a
volume of 24 dm3
Avogadro Constant = 6.02 x 1023 mol-1
Gas constant = 8.31 J mol-1 K-1
Planck Constant = 6.63 x 10-34 Js
Specific Heat Capacity of water = 4.2 J g-1 K-1
Speed of Light = 3 x 108 ms-1
Characteristic absorptions in IR spectroscopy
Wavenumber/cm-1
Bond
Compound
550 – 850
750 – 1100
1000 – 1300
1450 – 1650
1600 – 1700
1650 – 1800
C – X (X=Cl, Br, I)
C–C
C–O
C=C
C=C
C=O
2200 – 2300
2500 – 3200
2750 – 2850
2850 – 3000
3200 – 3600
3300 – 3500
C≡N
O–H
C–H
C–H
O–H
N–H
Haloalkanes
Alkanes, alkyl groups
Alcohols, esters, carboxylic acids
Arenes
Alkenes
Carboxylic acids, esters, aldehydes,
ketones, amides, acyl chlorides
Nitriles
Carboxylic acids
Aldehydes
Alkanes, alkyl groups, alkenes, arenes
Alcohols
Amines, amides
Proton Chemical Shifts in Nuclear Magnetic Resonance Spectroscopy
(relative to TMS)
Chemical Shift
Structure
0.5 – 2.0
0.5 – 5.5
1.0 – 3.0
2.0 – 3.0
2.0 – 4.0
–CH
–OH
–NH
–CO–CH
–N–CH
C6H5–CH
X–CH
4.5 – 6.0
5.5 – 8.5
6.0 – 8.0
9.0 – 10.0
10.0 – 12.0
–C=CH
RCONH
C6H5
–CHO
–COOH
Saturated alkanes
Alcohols
Amines
Ketones
Amines
Arene (aliphatic on ring)
X = Cl or Br (3.0 – 4.0)
X = I (2.0 – 3.0)
Alkenes
Amides
Arenes (on ring)
Aldehydes
Carboxylic acids
These chemical shifts are concentration and temperature dependent and may be outside
the ranges indicated above.
125
1
A sample of a mixture of hydrocarbons was injected into a GLC machine.
The trace obtained is shown below.
3
2
15
8
© CCEA
(a) What are the labels along the x axis and the y axis?
[2]
(b) How many substances are present in the sample?
[1]
(c) The relative areas of each signal are indicated on the trace.
Calculate the percentage purity of the major component in the mixture.
[2]
126
Examiner Only
Marks Re-mark
2
You are supplied with a mixture of two crystalline solids. The solids are
iron(II) sulfate and hydrated copper(II) sulfate.
Examiner Only
Marks Re-mark
(a) Describe the appearance of the mixture.
[2]
(b) The mixture was added to water and stirred with excess concentrated
ammonia solution. The mixture was filtered.
(i) State the name and colour of the solid obtained on the filter paper.
[2]
(ii) State the formula and the colour of the filtrate.
[2]
(iii) How would you show that the sulfate anion was present in the
filtrate?
127
[2]
[Turn over
3
The structure of 1-phenylazonaphth-2-ol is shown below:
Examiner Only
Marks Re-mark
HO
N
N
© CCEA
The preparation is as follows:
Dissolve 5.0 g of phenylamine in 16 cm3 of concentrated hydrochloric acid
and 16 cm3 of water contained in a small beaker. Diazotise by the addition
of a solution of 40 g of sodium nitrite in 20 cm3 of water. The temperature
is maintained at 0–5 °C. The aqueous solution of sodium nitrite is added
in portions until after 4 minutes the solution gives an immediate positive
test for excess of nitrous acid with moist potassium iodide starch paper.
Any precipitated phenylamine hydrochloride dissolves during the
diazotisation to give a clear solution of the highly soluble diazonium salt.
Prepare a solution of 7.0 g of naphth-2-ol in 45 cm3 of 10% sodium
hydroxide solution in a 250 cm3 beaker and cool the solution to 5 °C. Add
the cold diazonium salt solution very slowly. A red colour develops and
red crystals of 1-phenylazonaphth-2-ol soon separate. When all the
diazonium salt solution has been added allow the mixture to stand in an
ice bath for 30 minutes with occasional stirring. Filter the solution through
a Buchner funnel with gentle suction, wash well with water and drain
thoroughly by pressing the crystals. Recrystallise the product from pure
ethanoic acid. Filter the recrystallised product with suction, wash with a
little ethanol and dry between filter paper. The yield of deep red crystals is
3.0 g. The melting point is 131–2 °C.
(a) Explain why phenylamine is more soluble in hydrochloric acid than in
water.
[2]
(b) Explain why the temperature is maintained at 0–5 °C.
[2]
128
(c) Nitrous acid forms iodine which reacts with potassium iodide starch
paper.
Examiner Only
Marks Re-mark
Explain what a positive result will be.
[2]
(d) The diazonium salt contains a benzene ring.
Why would you expect it to be highly soluble in water?
[2]
(e) How would you adjust Buchner filtration to achieve gentle suction?
[2]
(f) What is the advantage in washing the 1-phenylazonaphth-2-ol with
ethanol?
[2]
(g) Explain how you would determine the melting point of
1-phenylazonaphth-2-ol.
129
[5]
[Turn over
(h) Calculate the percentage yield of 1-phenylazonaphth-2-ol to one
decimal place.
Examiner Only
Marks Re-mark
4
[5]
The compound nitramide, NO2NH2, is a white crystalline solid at room
temperature. It is readily soluble in water in which it decomposes at a
measurable rate according to:
NO2NH2(aq) → N2O(g)  H2O(l)
Nitrogen(I) oxide, is insoluble in water.
(a) (i) Draw a labelled diagram to show how you would carry out this
experiment and explain the procedure.
[5]
(ii) What is the main factor that needs to remain constant in the
experiment to obtain valid results?
[1]
130
(iii) A student suggested that a method of measuring the speed of the
reaction would be to count the number of bubbles which were
being produced.
Examiner Only
Marks Re-mark
Explain why this would not be a good method.
[1]
(iv) Suggest why nitramide is very soluble in water.
[2]
(b) Starting with 100 cm3 of a 0.50 M solution of nitramide in water the
volume of nitrogen(I) oxide evolved, measured at 20 °C and a
pressure of one atmosphere, was as follows:
volume of nitrogen(I)
oxide/cm3
time/seconds
0.0
5.60
11.20
18.0
22.4
0
500
1000
1500
2000
(i) Explain which one of these results would not be used in the
calculation of the rate of evolution of nitrogen(I) oxide.
[2]
(ii) Calculate the percentage of the nitramide, as a whole number,
that has decomposed after 1000 seconds.
[3]
(iii) Given that the initial reaction rate is 5  10–6 mol dm–3 s–1 and the
rate law is R  k[NO2NH2], calculate the rate constant for the
reaction and state its units.
131
[2]
[Turn over
(c) A proposed mechanism for the decomposition of nitramide is:
NH2NO2(aq) → NO2NH–(aq)  H(aq)
NO2NH–(aq) → N2O(g)  OH–(aq)
H(aq)  OH–(aq) → H2O(aq)
Examiner Only
Marks Re-mark
(i) Suggest and explain the rate determining step.
[2]
(ii) Give the formula of the reactive intermediate.
[1]
(iii) Suggest whether the proposed mechanism explains the order of
the reaction.
[2]
(d) Nitrogen(I) oxide is also formed when ammonium nitrate decomposes.
NH4NO3 → N2O  2H2O
(i) Describe how you could prove the presence of ammonium ions in
solid ammonium nitrate.
[3]
(ii) How could you distinguish between solid samples of ammonium
nitrate and nitramide?
[1]
132
THIS IS THE END OF THE QUESTION PAPER
133
BLANK PAGE
134
APPARATUS AND MATERIALS
DIVIDER FRONT
135
APPARATUS AND MATERIALS
DIVIDER BACK
136
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 3
Basic Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN
APPARATUS
AND
MATERIALS
LIST
137
Advice for centres
•
All chemicals used should be at least laboratory reagent specification and labelled with
appropriate safety symbols, e.g. irritant.
•
For centres running multiple sessions – candidates for the later session should be
supplied with clean, dry glassware. If it is not feasible then glassware from the first
session should be thoroughly washed, rinsed with deionised water and allowed to
drain.
•
nsure all chemicals are in date otherwise expected observations may not be
E
seen.
138
Each candidate must be supplied with safety goggles or glasses.
Question 1
Each candidate must be supplied with:
•
a piece of glass tubing, 3 mm in diameter and between 10 and 15 cm
long
•
a spatula
•
a heatproof mat
•
a Bunsen burner
•
a watch glass
•
a boiling tube
•
a test tube/boiling tube rack
•
a spatula
•
a heatproof mat
•
a Bunsen burner
•
a glass stirring rod
•
a test tube/boiling tube rack
•
a test tube/boiling tube holder
•
one 50 cm3 burette of at least class B quality
•
a funnel for filling the burette
•
a filter funnel and three sheets of filter paper
•
a retort stand and clamp
•
a beaker of 100 cm3 capacity
•
a beaker of 250 cm3 capacity
•
a measuring cylinder of 100 cm3 capacity
•
one 25 cm3 pipette of at least class B quality
•
a safety pipette filler
•
two conical flasks of 250 cm3 capacity
•
phenolphthalein indicator with dropper
139
•
Universal Indicator solution with dropper
•
a white tile or white paper
•
a wash bottle containing deionised/distilled water
•
nichrome wire
•
5 g of a 50/50 mixture of calcium hydroxide, which has been moistened with a few drops of
water (the water should be absorbed and not visible), and calcium carbonate granules/chips
(which are of greater particle size than the calcium hydroxide) labelled P and irritant
•
150 cm3 of 0.01 M hydrochloric acid labelled 0.01 M and corrosive/irritant
•
about 10 cm3 of a saturated solution of calcium hydroxide in a reagent bottle/beaker labelled
limewater (made fresh)
•
about 10 cm3 of dilute hydrochloric acid in a stoppered reagent bottle labelled dilute
hydrochloric acid and corrosive/irritant. This solution should be approximately 2 M.
•
bout 10 cm3 of concentrated hydrochloric acid in a stoppered reagent bottle labelled
a
concentrated hydrochloric acid and corrosive
Question 2
Each candidate must be supplied with:
•
three test tubes
•
a test tube/boiling tube holder
•
a test tube/boiling tube rack
•
a spatula
•
a heatproof mat
•
a Bunsen burner
•
deionized/distilled water
•
20 cm3 of ethanol labelled Y and flammable
•
20 cm3 of propanone labelled X and flammable
•
20 cm3 of propanone mixed with a few drops of water labelled Z and flammable
•
3 rice grain sized pieces of sodium (they may still contain oil)
140
Question 3
•
3 g of citric acid labelled Q and irritant
•
a heatproof mat
•
a Bunsen burner
•
two pieces of broken porcelain not less than 2 cm in width
•
a pair of tongs
AS 3 Chemistry Practical Risk Assessment
Chemical
Notes
Emergency action
Hydrochloric
Low hazard
In the eye: flood the eye with gently-running tap water for 10
acid
Even at this low minutes. See a doctor.
(2 and 0.01 M)
concentration it Swallowed: do no more than wash out the mouth with water. Do
may still cause not induce vomiting. Sips of water may help cool the throat and
harm in the
help keep the airway open. See a doctor.
eyes or in a
Spilt on the skin or clothing: remove contaminated clothing.
cut.
Especially with concentrated acid, quickly use a dry cloth or paper
towel to wipe as much liquid as possible off the skin. Then drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: wipe up small amounts with a
damp cloth and rinse it well. For larger amounts, and especially
for (moderately) concentrated acid, cover with mineral absorbent
(e.g. cat litter) and scoop into a bucket. Neutralise with sodium
carbonate. Rinse with plenty of water.
In the eye: flood the eye with gently-running tap water for at
Calcium
IRRITANT
least 20 minutes. See a doctor. If a visit to hospital is necessary,
hydroxide
Irritating to the continue washing the eye during the journey in an ambulance.
eyes and skin. Swallowed: do no more than wash out the mouth with water. Do
not induce vomiting. Sips of water may help cool the throat and
help keep the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing.
Drench the skin with plenty of water. If a large area is affected or
blistering occurs, see a doctor.
Spilt on the floor, bench, etc.: wipe up small amounts with a damp
cloth and rinse it well. For larger amounts, and especially for
(moderately) concentrated solutions, cover with mineral absorbent
(e.g. cat litter) and scoop into a bucket. Neutralise with citric acid.
Rinse with plenty of water.
Phenolphthalein Not classified
In the eye: flood the eye with gently-running tap water for at least
as hazardous
10 minutes. See a doctor.
but should
Swallowed: do no more than wash out the mouth with water. Do
be used with
not induce vomiting. Sips of water may help cool the throat and
caution. Skin
help keep the airway open. See a doctor.
contamination
Spilt on the skin or clothing: remove contaminated clothing. Wash
should be
off the skin with soap and plenty of water. Rinse contaminated
avoided.
clothing.
Spilt on the floor, bench, etc.: wipe up with a damp cloth and rinse
it well.
141
Citric acid
IRRITANT
It is irritating to
eyes.
It is an
approved food
additive, E330.
Chemical
Calcium
carbonate
Notes
Low hazard
Ethanol
There is a
serious risk of
liquid catching
fire; its vapour
may catch fire
above
13°C.
Breathing
vapour may
result in
sleepiness
In the eye: flood the eye with gently-running tap water for 10
minutes. See a doctor if pain persists.
Swallowed: do no more than wash out the mouth with water. Do
not induce vomiting. Sips of water
may help cool the throat and help keep the airway open. See a
doctor.
Spilt on the skin or clothing: remove contaminated clothing. Then
drench the skin with plenty of water.
Spilt on the floor, bench, etc.: wipe up small amounts with a damp
cloth and rinse it well.
For large spills, cover with mineral absorbent (e.g. cat litter) and
scoop into a bucket. Neutralise with sodium carbonate. Rinse with
plenty of water.
Emergency action
Calcium carbonate occurs naturally as marble, chalk and
limestone.
It decomposes if heated above 800 °C and gives carbon dioxide
with acids (unless the calcium salt is insoluble). It is an approved
food additive, E170. Blackboard chalk may be calcium carbonate
but is more likely to be calcium sulfate.
In the eye: flood the eye with gently-running tap water for 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do
not induce vomiting. Sips of water may help cool the throat and
help keep the airway open. See a doctor. NB: The casualty may
show signs of drunkenness.
Spilt on the skin or clothing: remove contaminated clothing and
rinse it. Wash the affected area and clothing with plenty of water.
Clothing catches fire – smother flames on clothing or the skin with
a fire blanket or other material. Cool any burnt skin with gentlyrunning tap water for 10 minutes.
Other ethanol fires: allow fires in sinks, etc. to burn out. Fires at
the top of test tubes, beakers, etc. should be smothered with a
damp cloth or heat-proof mat.
Spilt on the floor, bench, etc.: extinguish all Bunsen-burner flames.
Wipe up small amounts with a cloth and rinse it well. For larger
amounts, open all windows, cover with mineral absorbent (e.g. cat
litter), scoop into a bucket and add water.
NB. Ethanol should not be heated with a Bunsen burner. If
heating is required, place the test tube of ethanol in a beaker
of boiling water from a kettle (the beaker should be on a
heatproof mat).
142
Calcium
hydroxide
It is not officially
classified, but
there is a risk of
serious damage
to the eyes. It is
irritating to the
skin, lungs, etc.
For a 15-minute
exposure, the
concentration of
the powder in the
atmosphere
should not exceed
15 mg m-3
Solid: flood the eye with gently-running tap water for at least
20 minutes. See a doctor. If a visit to hospital is necessary,
continue washing the eye during the journey in an ambulance.
Limewater is unlikely to cause serious problems; flood the eye
with gently-running tap water for at least 10 minutes. See a
doctor if there are any concerns.
Swallowed: Do no more than wash out the mouth with water.
Do not induce vomiting. Sips of water may help cool the throat
and help keep the airway open. Limewater is unlikely to cause
serious problems. Wash out the mouth. See a doctor if there
are any concerns.
Spilt on the skin or clothing: Brush off the solid. Remove
contaminated clothing. Drench the skin with plenty of water. If
a large area is affected or blistering occurs, see a doctor. For
limewater, wash with water.
Spilt on the floor, bench, etc. Wipe up limewater or small
amounts of solid with a damp cloth and rinse it well. For larger
amounts of solid, scoop into a bucket, add water to the area
followed by mineral absorbent (e.g. cat litter).
Chemical
Propanone
Notes
There is a serious
risk of the liquid
catching fire.
Its vapour may
catch fire above
-20°C.
It can cause
severe eye
damage and will
degrease the skin.
For a 15-minute
exposure, the
concentration in
the atmosphere
should not exceed
3620 mg m-3.
The smell can be
detected by most
Emergency action
In the eye: flood the eye with gently-running tap water for 10
minutes. See a doctor.
Vapour breathed in: remove the casualty to fresh air. Keep
him/her warm. See a doctor if breathing is difficult.
Swallowed: do no more than wash out the mouth with water.
Do not induce vomiting. Sips of water may help cool the throat
and help keep the airway open. See a doctor.
Clothing catches fire: smother flames on clothing or the skin
with a fire blanket or other material. Cool any burnt skin with
gently-running tap water for 10 minutes.
Other propanone fires: allow fires in sinks, etc. to burn
out. Fires at the top of test tubes, beakers, etc. should be
smothered with a damp cloth or heat-proof mat.
Spilt on the skin or clothing: remove contaminated clothing. If
more than a test-tube amount was involved, wash the
affected area and clothing with plenty of water.
Spilt on the floor, bench, etc.: put out all Bunsen-burner
flames. Wipe up small amounts with a cloth and rinse it well.
For larger amounts, open all windows, cover with mineral
absorbent (e.g. cat litter), scoop into a bucket and add water.
143
Concentrated
hydrochloric acid
CORROSIVE
In the eye: flood the eye with gently-running tap water for 10
minutes. See a doctor.
It causes
Vapour breathed in: remove to fresh air. Call a doctor if breathing
burns. The
is difficult.
vapour irritates Swallowed: do no more than wash out the mouth with water. Do
the lungs.
not induce vomiting. Sips of water may help cool the throat and
help keep the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Then
drench the skin with plenty of water. If a large area is affected or
blistering occurs, see a doctor.
Spilt on the floor, bench, etc.: for release of gas, consider the
need to evacuate the laboratory and open all windows. For large
spills, and especially for (moderately) concentrated acid, cover
with mineral absorbent (e.g. cat litter) and scoop into a bucket.
Neutralise with sodium carbonate. Rinse with plenty of water.
Wipe up small amounts with a damp cloth and rinse it well.
Chemical
Limewater
Notes
Sodium
Reacts
violently with
water.
It burns
vigorously and
is difficult to
extinguish.
It causes
burns contact
with moisture
produces
sodium
hydroxide
which is
corrosive
It reacts
violently
with many
substances
Emergency action
Even a saturated solution of calcium hydroxide is so dilute that
it is not classed as irritant. However, sometimes the solution is
made up from solid calcium hydroxide which is irritating to the
eyes and skin.
In the eye: flood the eye with gently-running tap water for at
least 20 minutes. See a doctor. If it is necessary to go to hospital,
continue washing the eye during the journey in an ambulance.
Swallowed: do no more than wash out the mouth with water. Do
not induce vomiting. Sips of water may help cool the throat and
help keep the airway open. See a doctor.
Spilt on the skin or clothing: remove any pieces of solid with
forceps. Then drench the skin with plenty of water. If a large
area is affected or blistering occurs, see a doctor.
Metal catches fire: smother with dry sand, anhydrous sodium
carbonate or mineral absorbent (e.g. cat litter).
Spilt on the floor, bench, etc.: scoop up as much metal as
possible into a dry container. Cover the area with dry sand or
anhydrous sodium carbonate and scoop into a dry bucket for
further treatment. Rinse the area with plenty of water and mop.
144
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2018
Chemistry
Assessment Unit A2 3
Further Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN
APPARATUS
AND
MATERIALS
LIST
145
Advice for centres
•
All chemicals used should be at least laboratory reagent specification and labelled with
appropriate safety symbols, e.g. irritant.
•
For centres running multiple sessions – candidates for the later session should be supplied
with clean, dry glassware. If it is not feasible then glassware from the first session should
be thoroughly washed, rinsed with deionised water and allowed to drain.
•
Ensure all chemicals are in date otherwise expected observations may not be seen.
146
Each candidate must be supplied with safety goggles or glasses.
Question 1
Each candidate must be supplied with:
•
one 50 cm3 burette of at least class B quality
•
a funnel for filling the burette
•
a retort stand and clamp
•
a beaker of 100 cm3 capacity
•
a beaker of 250 cm3 capacity
•
a measuring cylinder of 100 cm3 capacity
•
one 25 cm3 pipette of at least class B quality
•
a safety pipette filler
•
two conical flasks of 250 cm3 capacity
•
a white tile or white paper
•
a wash bottle containing deionised/distilled water
•
150 cm3 of 0.20 M potassium manganate(VII) labelled 0.20 M and irritant
•
150 cm3 of sodium ethandioate solution in a stoppered reagent bottle or beaker labelled
sodium ethandioate and toxic. This solution should contain 62 gdm-3 of sodium ethandioate.
•
80 cm3 of 2 M dilute sulfuric acid in a stoppered reagent bottle or beaker labelled sulfuric acid
portions and corrosive
Question 2
Each candidate must be supplied with:
•
six test tubes
•
a test tube/boiling tube rack
•
a spatula
•
a dropping pipette
•
deionised/distilled water
•
2 g of iron(II) sulfate labelled iron compound and irritant
•
10 cm3 of 1 M dilute sodium hydroxide solution labelled sodium hydroxide solution and
corrosive
147
•
10 cm3 of 2 M dilute ammonia solution labelled dilute ammonia solution and irritant
•
10 cm3 of 0.2 M barium chloride solution labelled barium chloride solution and irritant
•
0 cm3 of 0.2 M silver nitrate solution labelled silver nitrate solution and irritant
Question 3
Test tubes and measuring cylinder used in previous questions could be re-used in this question. If not
six test tubes have been recommended. Although a burette and pipette are not listed below they could
be used from question 1.
•
six test tubes
•
one 100 cm3 measuring cylinder
•
one 25 cm3 measuring cylinder
•
a test tube/boiling tube rack
•
40 cm3 of 5 M copper(II) sulfate solution labelled X
•
20 cm3 of 2 M copper(II) sulfate solution labelled Y
Question 4
•
two capillary tubes
•
one ignition tube a third filled with propanone
•
one TLC plate to fit a 250 cm3 beaker
•
a pair of scissors or scissors to be made available to groups of candidates
•
one 250 cm3 beaker with a lid which can be of any design e.g. cardboard
•
a container of iodine crystals which will fit a TLC plate
•
20 cm3 of ethanol labelled ethanol and flammable
•
Z is a mixture of a crystal/grain of benzoic acid mixed with a crystal/grain of naphthalene
148
Question 5
Test tubes used in previous questions could be re-used in this question. If not six test tubes have been
recommended.
•
six test tubes
•
a test tube/boiling tube rack
•
20 cm3 of 0.2 M copper(II) sulfate solution labelled copper(II) sulfate solution and irritant
•
20 cm3 of 0.2 M ammonia solution labelled ligand 1 solution and irritant
•
20 cm3 of 0.2 M ethylene diamine solution labelled ligand 2 solution and irritant
•
20 cm3 of 0.2 M edta (disodium salt) solution labelled ligand 3 solution and irritant
A23 Chemistry Practical Risk Assessment
Question 1
Chemical
Sulfuric acid
(2 M)
Sodium
ethandioate
Notes
Low hazard
Even at this low
concentration it
may still cause
harm
in the eyes or in
a cut.
Emergency action
In the eye: flood the eye with gently-running tap water for 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do
not induce vomiting. Sips of water may help cool the throat and
help keep the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing.
Especially with concentrated acid, quickly use a dry cloth or paper
towel to wipe as much liquid as possible off the skin. Then drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: wipe up small amounts with a
damp cloth and rinse it well. For larger amounts, and especially
for (moderately) concentrated acid, cover with mineral absorbent
(e.g. cat litter) and scoop into a bucket. Neutralise with sodium
carbonate. Rinse with plenty of water.
In the eye: flood the eye with gently-running tap water for 10
Soluble salts of
oxalic acid (e.g.
minutes. See a doctor if pain persists.
sodium and
Swallowed: do no more than wash out the mouth with water. Do
potassium) are as not induce vomiting. Sips of water may help cool the throat and
hazardous as the help keep the airway open. See a doctor.
acid.
Spilt on the skin or clothing: remove contaminated clothing. Then
drench the skin with plenty of water.
Spilt on the floor, bench, etc.: wipe up small amounts with a damp
cloth and rinse it well. For large spills, cover with mineral absorbent
(e.g. cat litter) and scoop into a bucket. Rinse with plenty of water.
149
Potassium
It is harmful
manganate(VII) if swallowed
and stains
the hands
and clothing.
Many
hazardous
reactions
occur with
reducing
agents or
concentrated
acids
In the eye: flood the eye with gently-running tap water for at least 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing and rinse
it. Wash off the skin with plenty of water.
Manganate(VII) will give permanent stains to clothing and the skin. If
skin contamination is more than small, see a doctor.
Spilt on the floor, bench, etc.: wear eye protection and gloves. Scoop
up the solid. Rinse the area with water and wipe up.
Question 2
Chemical
Iron(II)
sulfate
Notes
Harmful if
swallowed.
Barium
chloride
Solution
Low hazard
Sodium
hydroxide
solution
It causes
severe
burns; it is
particularly
dangerous to
the eyes.
Emergency action
In the eye: flood the eye with gently-running tap water for at least 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Dust breathed in: remove the casualty to fresh air. See a doctor if
breathing is difficult.
Spilt on the skin or clothing: remove contaminated clothing and rinse
it. Wash off the skin with plenty of water.
Spilt on the floor, bench, etc.: scoop up solid (take care not to raise
dust). Wipe up small solution spills or any traces of solid with cloth; for
larger spills use mineral absorbent (e.g. cat litter).
In the eye: flood the eye with gently-running tap water for at least 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: brush off any solid. Remove
contaminated clothing. Drench the skin with plenty of water. If a large
area is affected or blistering occurs, see a doctor. Rinse contaminated
clothing with water.
Spilt on the floor, bench, etc.: rinse the area with water, diluting
greatly. Solutions should be treated with mineral absorbent (e.g. cat
litter).
In the eye: flood the eye with gently-running tap water for at least
20 minutes. See a doctor. If a visit to hospital is necessary, continue
washing the eye during the journey in an ambulance.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: wipe up small amounts with a damp
cloth and rinse it well. For larger amounts, and especially for
(moderately) concentrated solutions, cover with mineral absorbent
(e.g. cat litter) and scoop into a bucket. Neutralise with citric acid.
Rinse with plenty of water.
150
Chemical
Dilute
Ammonia
solution
Notes
It may still
cause harm
in eyes or in
a cut.
Low hazard
Silver
nitrate
solution
Very dilute
solutions are
adequate for
most school
work when
testing for
halides in
solution.
Emergency action
In the eye: flood the eye with gently-running tap water for at least 20
minutes (for alkalis). See a doctor. If it is necessary to go to hospital,
continue washing the eye during the journey in an ambulance.
Vapour breathed in: remove the casualty to fresh air. Call a doctor if
breathing is difficult.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep the
airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Drench the
skin with plenty of water. If a large area is affected or blistering occurs,
see a doctor.
Spilt on the floor, bench, etc.: if large amounts are spilt and especially for
(moderately) concentrated solutions. Cover with mineral absorbent (e.g.
cat litter) and scoop into a bucket. Neutralise with citric acid. Rinse with
plenty of water. Wipe up small amounts with a damp cloth and rinse it
well.
In the eye: flood the eye with gently-running tap water for at least 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep the
airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing and rinse it.
Wash off the skin with plenty of water. If the silver nitrate produces more
than small burns, see a doctor.
Spilt on the floor, bench, etc.: wear eye protection and gloves. Scoop up
the solid. Rinse the area with water and wipe up, rinsing repeatedly. Rinse
the mop or cloth thoroughly.
Question 3
Copper(II)
sulfate
Solution
Harmful if
swallowed;
the solid may
irritate the
eyes and
skin
In the eye: flood the eye with gently-running tap water for at least 10
minutes. See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep the
airway open. See a doctor.
Dust breathed in: remove the casualty to fresh air. See a doctor if
breathing is difficult.
Spilt on the skin or clothing: remove contaminated clothing and rinse it.
Wash off the skin with plenty of water.
Spilt on the floor, bench, etc.: scoop up solid (take care not to raise dust).
Wipe up small solution spills or any traces of solid with cloth; for larger
spills use mineral absorbent (e.g. cat litter).
151
Question 4
Chemical
Iodine
Propanone
Notes
It is harmful
if breathed in
or by contact
with the skin. It
causes
burns to the
skin if left for
some time.
Emergency action
In the eye: flood the eye with gently-running tap water for 10 minutes.
See a doctor.
Vapour breathed in: remove the casualty to fresh air. Call a doctor if
breathing is even slightly affected.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: brush off solid iodine and immerse
in sodium thiosulfate solution (20%, 1 M). Remove contaminated
clothing, soak it and drench the skin with plenty of water. See a doctor
if a large area is affected or blistering occurs.
Spilt on the floor, bench, etc.: scoop up any solid iodine, add sodium
thiosulfate solution (20%, 1 M) to the remaining spill and leave for 1
hour. Mop up and rinse with plenty of water.
There is a
In the eye: flood the eye with gently-running tap water for 10 minutes.
See a doctor.
serious risk
of the liquid
Vapour breathed in: remove the casualty to fresh air. Keep him/her
warm. See a doctor if breathing is difficult.
catching fire.
Its vapour may Swallowed: do no more than wash out the mouth with water. Do not
catch fire above induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
-20°C.
Clothing catches fire: smother flames on clothing or the skin with a
It can cause
fire blanket or other material. Cool any burnt skin with gently-running
severe eye
tap water for 10 minutes.
damage and
Other propanone fires: allow fires in sinks, etc. to burn out. Fires at
will degrease
the top of test tubes, beakers, etc. should be smothered with a damp
the skin.
cloth or heat-proof mat.
Spilt on the skin or clothing: remove contaminated clothing. If more
than a test-tube amount was involved, wash the affected area and
clothing with plenty of water.
Spilt on the floor, bench, etc.: put out all Bunsen-burner flames. Wipe
up small amounts with a cloth and rinse it well. For larger amounts,
open all windows, cover with mineral absorbent (e.g. cat litter), scoop
into a bucket and add water.
152
Chemical
Ethanol
Notes
There is a
serious risk of
liquid catching
fire; its vapour
may catch
fire above 13°C.
The vapour /
air mixture is
explosive (from
3.3 to 19%
ethanol).
Breathing vapour
may result in
sleepiness:
Emergency action
In the eye: flood the eye with gently-running tap water for 10 minutes.
See a doctor.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor. NB: The casualty may show signs of
drunkenness.
Spilt on the skin or clothing: remove contaminated clothing and rinse it.
Wash the affected area and clothing with plenty of water.
Clothing catches fire: smother flames on clothing or the skin with a fire
blanket or other material. Cool any burnt skin with gently-running tap
water for 10 minutes.
Other ethanol fires: allow fires in sinks, etc. to burn out. Fires at the top
of test tubes, beakers, etc. should be smothered with a damp cloth or
heat-proof mat.
Spilt on the floor, bench, etc.: extinguish all Bunsen-burner flames.
Wipe up small amounts with a cloth and rinse it well. For larger
amounts, open all windows, cover with mineral absorbent (e.g. cat
litter), scoop into a bucket and add water.
Notes
It may still cause
harm in eyes or
in a cut.
Emergency action
In the eye: flood the eye with gently-running tap water for at least 20
minutes (for alkalis). See a doctor. If it is necessary to go to hospital,
continue washing the eye during the journey in an ambulance.
Vapour breathed in: remove the casualty to fresh air. Call a doctor if
breathing is difficult.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: if large amounts are spilt and
especially for (moderately) concentrated solutions. Cover with mineral
absorbent (e.g. cat litter) and scoop into a bucket. Neutralise with citric
acid. Rinse with plenty of water. Wipe up small amounts with a damp
cloth and rinse it well.
Question 5
Chemical
Dilute
Ammonia
solution
Low hazard
153
Chemical
Ethylene
diamine
solution
Notes
CLEAPSS
hazard sheet not
available
Treat as
hazardous as
ammonia
Chemical
EDTA
Notes
CLEAPSS
hazard sheet
not available
Treat as
hazardous as
ammonia
Emergency action
In the eye: flood the eye with gently-running tap water for at least 20
minutes (for alkalis). See a doctor. If it is necessary to go to hospital,
continue washing the eye during the journey in an ambulance.
Vapour breathed in: remove the casualty to fresh air. Call a doctor if
breathing is difficult.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: if large amounts are spilt and
especially for (moderately) concentrated solutions. Cover with mineral
absorbent (e.g. cat litter) and scoop into a bucket. Neutralise with citric
acid. Rinse with plenty of water. Wipe up small amounts with a damp
cloth and rinse it well.
Emergency
In the eye: flood the eye with gently-running tap water for at least 20
minutes (for alkalis). See a doctor. If it is necessary to go to hospital,
continue washing the eye during the journey in an ambulance.
Swallowed: do no more than wash out the mouth with water. Do not
induce vomiting. Sips of water may help cool the throat and help keep
the airway open. See a doctor.
Spilt on the skin or clothing: remove contaminated clothing. Drench
the skin with plenty of water. If a large area is affected or blistering
occurs, see a doctor.
Spilt on the floor, bench, etc.: if large amounts are spilt and
especially for (moderately) concentrated solutions. Cover with mineral
absorbent (e.g. cat litter) and scoop into a bucket. Neutralise with citric
acid. Rinse with plenty of water. Wipe up small amounts with a damp
cloth and rinse it well.
154
MARK SCHEME
DIVIDER FRONT
155
MARK SCHEME
DIVIDER BACK
156
General Certificate of Education
Chemistry
GENERAL MARKING
INSTRUCTIONS
157
General Marking Instructions
Introduction
The main purpose of the mark scheme is to ensure that examinations are marked accurately,
consistently and fairly. The mark scheme provides examiners with an indication of the nature
and range of candidates’ responses likely to be worthy of credit. It also sets out the criteria
which they should apply in allocating marks to candidates’ responses.
Assessment objectives
Below are the assessment objectives for GCE Chemistry:
Candidates should be able to:
AO1
Demonstrate knowledge and understanding of scientific ideas, processes, techniques
and procedures.
AO2
Apply knowledge and understanding of scientific ideas, processes, techniques and
procedures:
• in a theoretical context
• in a practical context
• when handling quantitative and qualitative data
AO3
Analyse, interpret and evaluate scientific information, ideas and evidence (in relation
to particular issues)
• make judgements and reach conclusions
• develop and refine practical design and procedures
Quality of candidates’ responses
In marking the examination papers, examiners should be looking for a quality of response
reflecting the level of maturity which may reasonably be expected of a 17 or 18-year-old which
is the age at which the majority of candidates sit their GCE examinations.
Flexibility in marking
Mark schemes are not intended to be totally prescriptive. No mark scheme can cover all the
responses which candidates may produce. In the event of unanticipated answers, examiners
are expected to use their professional judgement to assess the validity of answers. If an
answer is particularly problematic, then examiners should seek the guidance of the Supervising
Examiner.
Positive marking
Examiners are encouraged to be positive in their marking, giving appropriate credit for what
candidates know, understand and can do rather than penalising candidates for errors or
omissions. The exception to this for GCE Chemistry is when Examiners are marking complex
calculations and mechanisms when the Examiners are briefed to mark by error or omission.
Examiners should make use of the whole of the available mark range for any particular question
and be prepared to award full marks for a response which is as good as might reasonably be
expected of a 17 or 18-year-old GCE candidate.
Awarding zero marks
Marks should only be awarded for valid responses and no marks should be awarded for an
answer which is completely incorrect or inappropriate.
158
Marking Calculations
In marking answers involving calculations, examiners should apply the ‘carry error through’
rule so that candidates are not penalised more than once for a computational error. To avoid a
candidate being penalised, marks can be awarded where correct conclusions or inferences are
made from their incorrect calculations.
Types of mark schemes
Mark schemes for tasks or questions which require candidates to respond in extended written
form are marked on the basis of levels of response which take account of the quality of written
communication.
Other questions which require only short answers are marked on a point for point basis with
marks awarded for each valid piece of information provided.
Levels of response
In deciding which level of response to award, examiners should look for the number of indicative
content points in candidate responses to ensure that the answer has been written to coincide
with the question. In deciding which mark within a particular level to award to any response,
quality of communication will be assessed and examiners are expected to use their professional
judgement.
The following guidance is provided to assist examiners.
•
•
Threshold performance: Response which just merits inclusion in the level but the
quality of communication is basic should be awarded a mark at the bottom of the
range.
High performance: Response which fully satisfies the level description for both
content and quality of communication should be awarded a mark at the top of the
range.
Quality of written communication
Quality of written communication is taken into account in assessing candidates’ responses to
all tasks and questions on theory examination papers that require them to respond in extended
written form. These tasks and questions are marked on the basis of levels of response. The
description for each level of response includes reference to the quality of written communication.
For conciseness, quality of written communication is distinguished within levels of response as
follows:
Level C: Quality of written communication is basic.
Level B: Quality of written communication is good.
Level A: Quality of written communication is excellent.
In interpreting these level descriptions, examiners should refer to the more detailed guidance
provided below:
Level C (Basic): Basic reference to scientific terminology. The candidate makes only a limited
selection and use of an appropriate form and style of writing. The organisation of material may
lack clarity and coherence. There is little use of specialist vocabulary. Presentation, spelling,
punctuation and grammar may be such that intended meaning is not clear.
159
Level B (Good): Good reference to scientific terminology. The candidate makes a reasonable
selection and use of an appropriate form and style of writing. Relevant material is organised
with some clarity and coherence. There is some use of appropriate specialist vocabulary.
Presentation, spelling, punctuation and grammar are sufficiently competent to make meaning
clear.
Level A (Excellent): Excellent reference to scientific terminology. The candidate successfully
selects and uses the most appropriate form and style of writing. Relevant material is organised
with a high degree of clarity and coherence. There is widespread and accurate use of
appropriate specialist vocabulary. Presentation, spelling, punctuation and grammar are of a
sufficiently high standard to make meaning clear.
160
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 1
assessing
Basic Concepts in Physical
and Inorganic Chemistry
[CODE]
SPECIMEN
MARK
MARK
SCHEME
SCHEME
161
/ denotes alternative points
AVAILABLE
MARKS
Section A
1 B
[1]
2 C
[1]
3 D
[1]
4A
[1]
5 B
[1]
6A
[1]
7 D
[1]
8A
[1]
9A
[1]
10 C [1]
Total for Section A
162
10
Section B
AVAILABLE
MARKS
11 (a)(i) a region within an atom that can hold up to two electrons with
opposite spin [1]
(ii)
[1]
(iii)1s2 2s2 2p6 3s2 3p6 3d10 4s1[1]
(b)(i) all 8 ionisation energies showing an increase [1]
biggest increase is between 6th and 7th ionisation energy [1]
(ii)O+
(g)
→ O2+ (g) + e
[2]
[1]
(iii) O has smaller nuclear charge/one less proton [1]
(c)
outer electron is in the same shell so the shielding is similar [1]
less nuclear attraction on outermost electron in O [1]
[3]
going down the group the ionisation energy decreases [1]
the outermost electron is further from the nucleus [1]
the outermost electron experiences less shielding [1]
outer electron is attracted more strongly to the nucleus [1]
12(a) layers of positive ions [1]
sea of delocalised electrons [1]
[4]
13
[2]
(b)(i) atoms of the same element [1]
U235 has 143 neutrons U238 has 146 [1]
[2]
(ii) 237.979 = 235 x + 238 (100-x) /100
23797.9 = 235x + 23800 – 238 x
x = abundance of U235 = 0.7%; U238 = 99.3%
[3]
(c) (i)UF4 + 2Mg → U + 2MgF2[2]
(ii)UO2 + 4HF → UF4 + 2H2O [2]
(iii) +6 [1]
+6 [1]
+4 [1]
[3]
(d) (i) nitrogen(IV) oxide
[1]
(ii) relights glowing splint [1]
163
16
13(a) weak forces/van der Waals’ forces between layers [1]
layers can slide /slip off [1]
[2]
[2]
(c) no free charge carriers/free electrons/all electrons in covalent bonds[1]
(b) strong covalent bonds [1]
3d/giant tetrahedron [1]
14 (a)(i) moles = 0.287/143.4 = 0.002
ratio 1:1
0.002  107.9 = 0.216 g
error -1
[2]
(ii)Ag+ + e → Ag
[1]
AVAILABLE
MARKS
5
(b)Cu+ + Cl → Cu2+ + Cl–[1]
(c) (i) oxidation number of copper changes from +2 to +1 = reduction [1]
oxidation number of copper changes from 0 to +1 = oxidation [1]
oxidation and reduction of the same species (copper) in the same
reaction [1]
[3]
(ii) it is insoluble
(d)
[1]
moles of copper chloride = 2.0/134.5 = 0.01487
ratio 2HCl : 1 CuCl2
0.029747 = vol  1.0 /1000
volume = 29.7 cm3 = 30 cm3 to 2 sig figures
error -1
164
[3]
11
15(a) (i)Cl2 + 3F2 → 2ClF3[1]
AVAILABLE
MARKS
(ii) the electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
[2]
(iii)
Fx
x
x
F x Cl xx
x
F
[2]
F
(b)(i)
F
As
F
F
F


Cl
F
+


F
[1]
[1]
trigonal bipyramid [1]
five bonding pairs of electrons repel each other equally [1]
two bonding pairs of electrons and two lone pairs of electrons;
(c)(i)I+
bent/v/nonlinear [1]
the lone pairs of electrons repel more than bonding pairs [1] (ii)104.5°
[6]
[1]
Cl– [1]
chlorine is more electronegative than iodine [1]
[2]
(ii) chlorine has van der Waals’ forces between molecules [1]
iodine monochloride has permanent dipole-dipole attractions
between molecules [1]
permanent dipole-dipole attractions are stronger/intermolecular
forces stronger in ICl [1]
more energy needed to break the stronger intermolecular force [1]
[4]
165
18
16(a)
add dilute acid and effervescence for carbonate [1]
flame test yellow/orange for sodium ions [1]
add silver nitrate solution and ppt forms for halide [1]
dissolve in water [1]
AVAILABLE
MARKS
[4]
(b) (i) Indicative content
• in sodium strong attraction between positive ions and delocalised electrons
• in sodium metallic bonding
• in sodium chloride strong attraction between positive ion and
negative ion
• ionic bonding
• in iodine weak van der Waals forces between molecules
• ionic bonding is stronger than metallic bonding which is stronger than van der Waals
[6]
Band
Response
Mark
A
Candidates must use appropriate specialist terms to fully
explain the difference in melting point using a minimum of 6
points of indicative content. They must use good spelling,
punctuation and grammar and the form and style are of an
excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms to
explain the difference in melting point using a minimum of
4 points of indicative content. They must use satisfactory
spelling, punctuation and grammar and the form and style
are of a good standard.
[3]–[4]
C
Candidates explain partially the difference in melting point
using a minimum of 2 points of indicative content. They
use limited correct spelling, punctuation and grammar and
the form and style is of a basic standard.
[1]–[2]
D
Response not worthy of credit.
[0]
(ii) grey – black [1]
white [1]
[2]
(c)3I2 + 6NaOH → NaIO3 + 5NaI + 3H2O [2]
(d)(i)46  40 = 1840 g
1840/ 149.9 = 12.3 M
[2]
(ii) from colourless to yellow/brown 166
[1]
17
Total for Section B
80
Paper Total
90
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 2
assessing
Further Physical and Inorganic Chemistry
and an Introduction to Organic Chemistry
[CODE]
SPECIMEN
MARK
SCHEME
SCHEME
167
/ denotes alternative points
AVAILABLE
MARKS
Section A
1 C
[1]
2A
[1]
3A
[1]
4 B
[1]
5 B
[1]
6A
[1]
7 C
[1]
8 C
[1]
9 D
[1]
10 B [1]
Total for Section A
168
10
Section B
11
element
moles
AVAILABLE
MARKS
ratio
C
22.2 ÷ 12 = 1.85
2
H
3.7 ÷ 1 = 3.70
4
Br
74.1 ÷ 80 = 0.93
1
moles [1]
empirical Formula = C2H4Br [1]
216 ÷ 108 = 2
molecular Formula = C4H8Br2 [1]
12(a)CH3CH(CH3)CH2CH3 [1]
2-methylbutane [1]
[3]
CH3C(CH3)2CH3 [1]
2,2-dimethylpropane [1]
[4]
(b) molecules which have the same molecular formula but a different
structural formula.
[2]
(c) neopentane [1]
increased branching [1]
weaker van der Waals forces [1]
[3]
(d)C5H12  8O2 → 5CO2  6H2O
unbalanced [1]
balanced [1]
[2]
(e)initiation Cl2 → 2Cl • [1]
propagation Cl •  C5H12 → C5H11 •  HCl [1]
C5H11 •  Cl2 → C5H11Cl  Cl • [1]
termination Cl •  Cl • → Cl2 [1]
or
C5H11 •  C5H11 • → C10H22
or
C5H11 •  Cl • → C5H11Cl[4]
3
169
15
13(a) (i) enthalpy change(s) [1]
is/are independent of the route taken [1]
[2]
AVAILABLE
MARKS
(ii) enthalpy change which occurs when 1 mole of a substance [1] undergoes complete combustion in oxygen [1] under standard conditions. [1]
[3]
(iii)(–394)  (–286  2)  ( 75) [1]
(b)(i) average bond enthalpies are used
[1]
(ii) –698 = 4(C–H) – 2346
4(C–H) = 1648
412 kJ mol–1
error -1
[3]
(c) (i) Indicative content
• measure mass of spirit burner containing ethanol before and
after burning
• measure out known volume of water into a calorimeter using a burette
• burn the ethanol in the spirit burner and use the heat evolved to heat the water in the calorimeter
• measure initial and final temperature of water (after heating) using a thermometer
• calculate the heat evolved using the equation q = mc∆T
• calculate the number of moles of ethanol used from the mass of ethanol burned
• divide the heat evolved by the moles of ethanol used to calculate the enthalpy of combustion[6]
Band
–891 kJ mol–1 [1]
[2]
Response
Mark
A
Candidates must use appropriate specialist terms to explain
fully the process of determining the enthalpy of combustion
(using a minimum of 6 points of indicative content). They
use good spelling, punctuation and grammar and the form
and style are of an excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms to explain
the process of determining the enthalpy of combustion
(using a minimum of 5 points of indicative content). They
use good spelling, punctuation and grammar and the form
and style are of a good standard.
[3]–[4]
C
Candidates explain briefly and partially the process of
determining the enthalpy of combustion (using a minimum
of 4 points of indicative content). They use limited spelling,
punctuation and grammar and the form and style are of a
basic standard.
[1]–[2]
D
Response not worthy of credit.
[0]
(ii) incomplete combustion [1]
heat loss to surroundings [1]
[2]
170
19
14(a) peak shifts to right and peak is lower [2]
other drawing errors [–1]
[2]
AVAILABLE
MARKS
Number of
molecules
with a
given energy
Energy
Ea
© CCEA
(b) number of molecules with energy greater than Ea [1] increases [1] [2]
(c)
catalyst provides an alternative route [1]
of lower activation energy Ea [1]
more molecules have energy greater than Ea [1]
number/frequency of successful collisions (between SO2 and O2 molecules) increases [1]
[4]
15 (a)(i) the H atom in HBr has a + charge [1]
which is attracted to area of high electron density (in double
bond) [1]
(ii)
CH2 = CH2
H+
+
CH2 – CH2
CH2 – CH2
H
H
..
[3]
curly arrows drawn correctly [1]
Br−
[2]
Br
Br
−
error -1
[4]
171
8
(b)(i) CH – CH
3
2
CH3
Z isomer [1]
CH3 – CH2
C
C
C
C
CH3
E isomer [1]
(ii)
CH3
AVAILABLE
MARKS
H
H
CH3
[2]
CH3
CH CH2CCH2CH3
3
Br
major [1]
CH3
CH3CH2CHCHCH3
Br
minor [1]
[2]
(iii) carbocation intermediates produced [1]
(c)(i)C4H9Br + NaOH → C4H9OH + HBr tertiary carbocation more stable than secondary carbocation [1]
tertiary carbocation leads to formation of major product [1]
[3]
[2]
(ii) secondary [1]
carbon bonded to –OH is bonded to two other carbon atoms [1]
[2]
(d)(i)C4H9Br + NaOH → C4H8 + NaBr + H2O [2]
(ii) in ethanol
[1]
(iii)elimination
[1]
(iv)but-2-ene
[1]
172
22
16(a) rate of forward reaction = Rate of reverse reaction [1]
the amount of any given reactant or product remains constant [1]
(b) increase [1]
3 moles (g) LHS 2 moles (g) RHS
equilibrium shifts to RHS to oppose the change [1]
[2]
[2]
(c) decrease [1]
(forward) reaction is exothermic
equilibrium shifts to LHS to oppose the change/cool the system [1] [2]
(d) no effect on yield [1]
increases the rate of the forward and reverse reactions equally [1] [2]
(e)(i)Kc = [NO2]2/[NO]2[O2] [1]
mol–1 dm3 [1]
[2]
(ii)Kc > 1 AVAILABLE
MARKS
[1]
(f) 4 × 46
2 × 148 = 184/296 = 62.2%
error -1
173
[2]
13
Total for Section B
80
Paper Total
90
BLANK PAGE
174
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 3
assessing
Basic Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN
MARK
SCHEME
SCHEME
175
/ denotes alternative points
1(a) white
AVAILABLE
MARKS
[1]
(b) two different particle sizes are seen [1]
different shades of white [1]
[2]
(c)(i) no change at the start, possible vapour in the middle, (colourless)
liquid at the end (any 2 out of 3)
[2]
(ii) colourless, green colour (pH 7) [1]
(d)(i) fizzing/frothing/foaming/effervescence [1]
white solid left/some solid disappears [1]
(ii) limewater goes milky
[2]
[1]
(e)(i) measuring cylinder [1]
25 cm3 indicates an accuracy of 1 cm3 [1]
[2]
(ii) titre value/cm3 [2]
value of titration 20 cm3 +/– 2 cm3 = [2] +/– 4 cm3 = [1]
correct recording of values, e.g. decimal places and calculation
of titre [2]
[6]
(f) brick red [1]
2(a) X: sodium floats; no gas [1]
Y: sodium floats; lots of gas produced [1]
Z: sodium floats; not much gas [1]
[3]
(b) Y contains ethanol, fastest reaction
[1]
3(a)
substance melts
darkens/goes black
black solid left/ (most)disappears
error -1
18
4
[2]
(b) black solid (carbon) forms
176
[1]
3
Total for Booklet A
25
ADVANCED SUBSIDIARY (AS)
General Certificate of Education
2017
Chemistry
Assessment Unit AS 3
assessing
Basic Practical Chemistry
Practical Booklet B
[CODE]
SPECIMEN
MARK
SCHEME
SCHEME
177
/ denotes alternative points
1(a) changes from green to red
AVAILABLE
MARKS
[2]
(b) changes from green to red and there is some brown (bromine) present [2]
4
2
4
add water and stir to dissolve [1]
filter the mixture [1]
add hydrochloric acid to the solid [1]
it fizzes showing it is a carbonate [1]
filter the solution and add a soluble sulfate [1]
white precipitate produced [1]
to a maximum of [4]
3(a) sketch of apparatus ie gas passing through water/alkali [2]
explanation of how it works [1]
[4]
[3]
(b) acts as a catalyst for the reaction
(c) the speed of drops of liquid returning to the flask would increase with
vigorous refluxing
[1]
(d) a similar boiling point to the 1-chlorobutane
[1]
(e)water
[1]
[1]
(f) place in separating funnel with, e.g. water [1]
stopper the funnel [1]
invert the funnel [1]
shake and allow the liquids to separate and remove the lower one [1]
[4]
(g) used to dry the 1-chlorobutane [1]
anhydrous sodium sulfate [1]
[2]
(h)(i)gcm-3 [1]
0.81  23 = 18.63 g [1]
[2]
(ii) 18.63/74 = 0.25 mol ; 0.25 mol of C4H9Cl = 0.25 × 92.5 = 23.1 g
(i)
[2]
boiling points are usually measured in ranges [1]
a range of 1/2 degrees is the usual range [1]
the range is increased to collect as much as possible (if there are no
interfering compounds) [1] [3]
(j) compare the pure and “impure” spectra [1]
the “impure” spectrum will have extra peaks [1]
178
[2]
22
4(a) M(s) + H2O(g) →MO(s) + H2(g)
equation [1]
state symbols [1]
AVAILABLE
MARKS
[2]
(b) same mass [1]
same particle size [1]
100% purity [1]
[3]
(c)(i) steam is diluted water
or because steam is a gas and reacts more slowly than water
or despite the higher temperature steam is less concentrated than
water
or it’s like bromine and chlorine, chlorine is more reactive but it’s a
gas [1]
(ii) bubbles/fizzing effervescence [1]
white solid [1]
calcium moves up and down [1]
heat produced [1]
steam produced [1]
calcium dissolves/disappears [1]
to a maximum of [3]
[3]
(d) (i) time/seconds or minutes [1]
volume of hydrogen gas/cm3 [1]
[2]
(ii) steeper at the start [1]
earlier horizontal finish [1]
[2]
(iii) allow gas to go into a test tube [1]
(e) 3.4 g of Ca = 3.4/40 = 0.085 mol; 0.085 × 24 dm3 = 2.04 = 2.0 dm3 [4]
error -1
(f)
lighted splint [1]
pop noise [1]
[3]
the Group two metals are very reactive with oxygen [1]
hence the experiment would be over very quickly [1]
need to slow down the reaction [1]
only way is to dilute the oxygen [1]
e.g. by mixing it with nitrogen/noble gas [1]
collect the oxygen over water/in a syringe [1]
compare the rates of oxygen collection and relate
to reactivity [1]
to a maximum of [5]
179
[5]
25
Total for Booklet B
55
BLANK PAGE
180
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 1
assessing
Further Physical and Organic Chemistry
[CODE]
SPECIMEN
MARK
SCHEME
181
/ denotes alternative points
AVAILABLE
MARKS
Section A
1 B
[1]
2 D
[1]
3 C
[1]
4A
[1]
5 B
6 C
[1]
7 D
[1]
8 D
[1]
9 B
[1]
10 D [1]
[1]
Total for Section A
182
10
Section B
AVAILABLE
MARKS
11 (a)(i) H⦵ = ∑ fH⦵ (products) – ∑fH⦵ (reactants)
= [3 × −393.5] – [2 × −824.2]
= 467.9 kJ mol−1
[2]
S⦵ = ∑ S⦵ (products) − ∑ S⦵ (reactants)
G⦵ = H⦵ − TS⦵
= [(4 × 27.3) + (3 × 213.6)] − [(2 × 87.4) + (3 × 5.7)]
= 558.1 J K−1 mol-1[2]
= 467.9 − (298 × 0.5581)
= 301.6 kJ mol−1
(ii) G⦵ is positive
[1]
[1]
(b) T = (H⦵ ÷ S⦵)
= (467.9 ÷ 0.5581)
= 838K
[2]
12(a) the energy required to convert 1 mole [1] of an ionic solid into
gaseous ions [1][2]
(b)(i)
↑
↑
↑
Mg+(g) + e− + F2(g) [1]
↑
Mg2+(g) + 2F−(g)
↑
↑
Mg(s) + F2(g)
[1]
[1]
↓
MgF2(s)
[1]
[4]
(ii) LE = (+1123) + (150) + (736) + (1450) + (2  79) + (2  –348)
= 2921 kJ mol–1[2]
183
8
(c) (i)
H
H
H
O
O
Mg2+
AVAILABLE
MARKS
O
H
O
H
H
F−
[1]
H
H
[1]
[2]
(ii) LE = (–155) – [(–1920) + (2  –364)] = 2493 kJ mol–1[2]
13 (a)(i)2-hydroxy-2-methylbutanenitrile
[2]
(ii)optical
[1]
(iii)
H 5C 2
CH3
CH3
C
C
CN
NC
OH
HO
C 2H 5
correct 3D representation [1]
mirror image [1]
[2]
(iv) nucleophilic addition
[1]
(v)
O
−
O
C 2H 5
C
CH3
C 2H 5
C 2H 5
O
H+
C
CH3
CN
CH3
CN
CN−
−
C
OH
C 2H 5
C
CH3
CN
error –1
[4]
(vi) the carbonyl group is planar [1]
the nucleophile attacks from both sides to an equal extent [1]
equal amounts of each optical isomer formed [1]
[3]
(b)
heat [1] with
either acidified potassium dichromate, Tollens’ reagent or Fehling’s
solution [1]
correct positive result with butanal, no change with butanone [1]
[3]
184
12
(c)
NO2
CH3
C
CH3CH2
O + NH2N
H
NO2
AVAILABLE
MARKS
NO2
CH3
C
CH3CH2
(ii) Indicative content
NN
NO2
H
+H2O
[2]
•yellow/orange
•solid
• capillary tube
• heat slowly
• record the temperature when the solid melts
• compare to tables of data
Band
[6]
Response
Mark
A
Candidates must use appropriate specialist terms to
explain fully the process of identifying the ketone (using
a minimum of 6 points of indicative content). They use
good spelling, punctuation and grammar and the form
and style are of an excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms to
explain the process of identifying the ketone (using a
minimum of 5 points of indicative content). They use
good spelling, punctuation and grammar and the form
and style are of a good standard.
[3]–[4]
C
Candidates explain briefly and partially the process
of identifying the ketone (using a minimum of 4 points
of indicative content). They use limited spelling,
punctuation and grammar and the form and style are of
a basic standard.
[1]–[2]
D
Response not worthy of credit.
24
[0]
[CH3CH2COO−][H+] [CH3CH2COOH]
[1]
(ii) Ka = [H+]2 ÷ [CH3CH2COOH] [1]
[H+] = 0.00184 [1]
pH = 2.74 [1]
[3]
14(a) (i) Ka =
(iii) a solution which minimises changes in pH [1] on addition of small
amounts of acid or alkali [1]
[2]
(iv) moles of acid 0.25 × 0.3 = 0.075
moles of salt 0.15 × 0.2 = 0.03
(concentration of acid = 0.15 mol dm–3)
(concentration of salt = 0.06 mol dm–3)
[H+] = Ka × ([acid]/[salt]) = 3.38 × 10–5 mol dm–3)
pH = 4.47
185
[4]
(b) (i)CH3CH2COOH + NaOH → CH3CH2COONa + H2O[1]
AVAILABLE
MARKS
(ii) phenolphthalein [1]
colourless to pink [2]
range matches the vertical portion of the titration curve [1]
[4]
(iii) moles of NaOH = 0.20 × (18.5/1000) = 0.0037
moles of CH3CH2COOH = 0.0037
concentration of CH3CH2COOH = 0.148 mol dm–3[3]
(iv)[H+] = Kw ÷ [OH–] = 5 × 10–14 mol dm–3 [1]
pH = 13.30 [1]
[2]
20
15(a)
before
after
[2]
© CCEA
(b)(i)HNO3 + 2H2SO4 → NO2+ + H3O+ + 2HSO4–[2]
(ii) nitronium ion
[1]
(iii) electrophilic substitution
O
C
O
OCH3
C
+
NO2
H
NO2
O
C
OCH3
O
C
OCH3
NO2
H
OCH3
NO2
+ H+
error –1
[5]
(iv) methyl 3-nitrobenzoate
[1]
(v) cream solid
[1]
16(a) first [1]
valid explanation [1]
[2]
(b) zero [1]
valid explanation [1]
[2]
186
12
(c) rate = k[C4H9Br][1]
(d) 2000 [1]
s–1 [1]
(e)
[2]
CH3
C
H 3C
CH3
Br
RDS
C+
H 3C
CH3
CH3
H3C
C+
OH−
CH3
Br −
CH3
CH3
H 3C
C
OH
CH3
error –1
17 (a)(i)
[5]
H
H
C
OH
H
C
OH
H
C
OH
H
[1]
(ii) propane-1,2,3-triol
(iii)
AVAILABLE
MARKS
H
[1]
O
H
C
O
C
O
(CH2)7 ─ CH = CHCH2CH = CH(CH2)4CH3
H
C
O
C
O
(CH2)7 ─ CH = CHCH2CH = CH(CH2)4CH3
H
C
O
C
(CH2)7 ─ CH = CHCH2CH = CH(CH2)4CH3
H
[1]
187
12
(b) (i) 3-methylbutananoic aicd
methanol
(ii)
[1]
CH3
CH3
CH3 ─ C ─ CH2COOH + CH3OH
CH3 ─ C ─ CH2COOCH3 + H2O
H
AVAILABLE
MARKS
[2]
H
(iii) Indicative content
• acid and alcohol into round-bottomed flask and add concentrated sulfuric acid slowly
• add anti-bumping granules
• heat under reflux
• distill and collect at boiling point of ester
• shake with aqueous sodium carbonate and release pressure
• separate ester layer using separating funnel
• add a named drying agent
• decant/filter
[6]
Band
Response
Mark
A
Candidates must use appropriate specialist terms
to explain fully the preparation of the ester (using a
minimum of 6 points of indicative content). They use
good spelling, punctuation and grammar and the form
and style are of an excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms to
explain the preparation of the ester (using a minimum
of 5 points of indicative content). They use good
spelling, punctuation and grammar and the form and
style are of a good standard.
[3]–[4]
C
Candidates explain briefly and partially the preparation
of the ester (using a minimum of 4 points of indicative
content). They use limited spelling, punctuation
and grammar and the form and style are of a basic
standard.
[1]–[2]
D
Response not worthy of credit.
[0]
188
12
Total for Section B
100
Total
110
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 2
assessing
Analytical, Transition Metals, Electrochemistry
and Organic Nitrogen Chemistry
[CODE]
SPECIMEN
MARK
SCHEME
189
/ denotes alternative points
AVAILABLE
MARKS
Section A
1 D
[1]
2A
[1]
3 C
[1]
4 C
[1]
5 D
6 C
[1]
7 B
[1]
8 C
[1]
9 D
[1]
10 B [1]
[1]
Total for Section A
190
10
Section B
AVAILABLE
MARKS
11(a) anode 2H2 + 4OH– → 4H2O + 4e– [1]
cathode O2 + 2H2O + 4e– → 4OH– [1]
[2]
(b)2H2(g) + O2(g) → 2H2O(l) [2]
(c) advantages: renewable source of electricity/does not produce
pollution/silent [2]
12(a) dipolar ions [1]
strong attraction between opposite charges [1]
[2]
(b)2H2NCH(CH2SeH)COOH + Na2CO3 →
2H2NCH(CH2SeH)COONa + H2O + CO2
[2]
(c) (i)H2N-CH(CH2SeH)-CO-NH-CH(CH2SeH)-COOH [3]
(ii) induced fit mechanism lowers activation energy [1]
(iii) bell shaped curve and labelled axes [2]
13(a) (i) Zn + 2Fe3+ ↔ 2Fe2+ + Zn2+ [1]
(ii) E = +0.32 so reaction should proceed [1]
(b)(i)MnO4– + 5Fe2+ + 8H+ → Mn2+ + 4H2O + 5Fe3+ [1]
(ii) moles MnO4– = 26.0  10–3  0.02 = 0.52  10–3
moles Fe = 5  0.52  10–3 = 2.6  10–3 in 25 cm3
= 2.6  10–2 in 250 cm3
mass Fe = 2.6  10–2  56 = 1.456 g
% Fe = 1.456  100 = 91%
1.60
error - [1]
[4]
(iii) colourless to pink
[2]
14(a) (i) nucleophilic substitution
[1]
(ii)C4H9Br + NH3 → C4H9NH2 + HBr
[1]
δ+
δ–
(iii) C–Br polarised
lone pair on N/NH3 attracted to Cδ +
C–N bond formed, C–Br bond broken
[3]
(b) (i) lithal [1]
(ii)C3H7CN + 4[H] → C3H7CH2NH2 [2]
191
6
10
9
(c)C6H5NO2 + 6[H] → C6H5NH2 + 2H2O[2]
(d) (i) less basic than the others
AVAILABLE
MARKS
[1]
+
(ii)C6H5NH2 + HCl → C6H5NH3 Cl– [1]
(iii) phenylethyl group attached to N atom which has two hydrogens [1]
+
(e) (i)C6H5-N ≡ N [2]
[1]
[1]
(iii)A HCl/H2SO4 or NaOH
B lithal
[1]
C
HNO2/NaNO2 + HCl
[1]
D
PCl5/HCl[1]
(ii) sodium nitrite and dilute hydrochloric acid
15(a) transition metal ions have an incomplete d shell
[1]
(b) (i)VO2+(aq)
V3+(aq)
[2]
blue [1]
green [1]
(ii)3VO2+ + Cr + 6H+ → 3VO2+ + Cr3+ + 3H2O [2]
emf = 1.74 V [1]
[3]
(c) (i) blue [1]
yellow [1] [2]
(ii) octahedral [1]
(iii) hydrochloric acid/sodium chloride
[1]
(d) (i)H2N-CH2-CH2-NH2[1]
(ii) two coordinate bonds/points of attachment (iii)[Ni(en)3]2+[2]
(e) (i)Co(CH3COO)2.4H2O (ii) to oxidise cobalt(II) to cobalt(III)
[2]
(iii) octahedral [1]
(iv)six
[1]
20
[1]
[2]
(v) 1 dm3 of H2O2 produces 20 dm3 of oxygen
20/24 mole of oxygen = 0.833
i.e. 0.833 mol dm–3
2:1 ratio therefore 1.67 mol dm–3
error - [1]
192
[3]
23
AVAILABLE
MARKS
16 (a)(i) same molecular formula but different structural formula
[2]
[2]
(ii) HCOOH + C2H5OH
HCOOC2H5 + H2O (iii) add conc. H2SO4/methanoic acid/ethanol [1]
remove water [1]
(b)(i) Tetramethylsilane, Si(CH3)4
[2]
[2]
(ii) Indicative content
• HCOO – singlet – next to O
•CH2 – quartet – next to 3H
•CH3 – triplet – next to 2H
• ratio 1:2:3
• area under curve is proportional to the number of H in each
environment
•
•
Band
greatest deshielding
H next to O
[6]
Response
Mark
A
Candidates must use appropriate specialist terms to
explain fully the process of nmr (using a minimum of 6
points of indicative content). They use good spelling,
punctuation and grammar and the form and style are of
an excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms
to explain the process of nmr (using a minimum of 5
points of indicative content). They use good spelling,
punctuation and grammar and the form and style are of
a good standard.
[3]–[4]
C
Candidates explain briefly and partially the process of
nmr (using a minimum of 4 points of indicative content).
They use limited spelling, punctuation and grammar
and the form and style are of a basic standard.
[1]–[2]
D
Response not worthy of credit.
[0]
(c)28 C2H4+ or CO+ [1]
45HCOO+ or C2H5O+ [1]
(d) (i) bonds in molecules vibrate
absorb energy of a certain frequency
dependent on the atoms mass in the bond
-OH absorption peak for propanoic acid
different positions for C=O and C=O
|
|
OH
O
allow any 4 from the above 5 statements
[2]
193
[4]
AVAILABLE
MARKS
(ii) sodium carbonate [1]
effervescence with the acid [1]
[2]
17(a)C7H6O3 + C4H6O3 → C9H8O4 + C2H4O2
[2]
(b) aspirin is not very soluble in water.
(c) Indicative content
• TLC plate, pencil line, mark 3 spots
• dissolve small amounts of ‘crude’ aspirin, ‘purified’ aspirin and
‘pure’(commercial) aspirin in separate test tubes in a suitable solvent, e.g. ethanol
• spot each sample on to the TLC plate
• place in developing tank with a suitable solvent, e.g. ethyl ethanoate
• remove plate and mark the position of solvent front
• use UV light or a locating reagent
[6]
Band
22
[1]
Response
Mark
A
Candidates must use appropriate specialist terms to
explain fully the process of TLC (using a minimum of 5
points of indicative content). They use good spelling,
punctuation and grammar and the form and style are of
an excellent standard.
[5]–[6]
B
Candidates must use appropriate specialist terms to
explain the process of TLC (using a minimum of 4
points of indicative content). They use good spelling,
punctuation and grammar and the form and style are of
a good standard.
[3]–[4]
C
Candidates explain briefly and partially the process
of TLC (using a minimum of 3 points of indicative
content). They use limited spelling, punctuation
and grammar and the form and style are of a basic
standard.
[1]–[2]
D
Response not worthy of credit.
[0]
(d) cost or volatility
194
[1]
10
Total for Section B
100
Total
110
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 3
assessing
Further Practical Chemistry
Practical Booklet A
[CODE]
SPECIMEN
MARK
SCHEME
195
/ denotes alternative points
AVAILABLE
MARKS
1(a) use of starting values to one decimal place [1]
correct calculation of average titre [2]
rough value between 23.4 and 25.2 [1]
accuracy of titration value +/- 0.2 cm3 of 23.2 cm3 sliding scale for [2]
[6]
(b) read the bottom of the meniscus or allow a method taking into account the colour of the potassium manganate(VII)
[2]
(c) colourless to pink (b) green solution [1]
(c) green precipitate
[1]
(d) green precipitate
[1]
(e) white precipitate
[1]
(f) no reaction
[1]
(g) iron(II) sulfate [1]
(b) 2M (b) two substances [2]
2(a) green 10
[1]
7
3(a) the comparison of colours would be made by placing test tubes of the
solutions side by side until one colour exactly matched the other colour in intensity/depth [2]
explanation/description of how the 5M solution would have to be
appropriately diluted with the correct use of suitable apparatus,
e.g. measuring cylinders [2]
[4]
[1]
5
4(a) correct labelling of solvent front and starting point [1]
two spots labelled with appropriate sizes at approximately correct places [1]
solvent front near the top of the TLC slide [1]
[3]
[1]
196
4
5
Ligand 1 is ammonia solution ligand 2 is ethylene diamine solution ligand 3 is edta solution all of the ligands will form a blue complex; ligand 3 will displace ligand 2 which will displace ligand 1. In each case for a positive result there should be an appropriate colour change. For a negative result there is no change based on the original colour of the solutions. Hence 3 positive results and 3 negative results.
–[1] for each incorrect result [4]
Total for Booklet A
197
AVAILABLE
MARKS
4
30
BLANK PAGE
198
ADVANCED
General Certificate of Education
2018
Chemistry
Assessment Unit A2 3
assessing
Further Practical Chemistry
Practical Booklet B
[CODE]
SPECIMEN
MARK
SCHEME
199
/ denotes alternative points
1(a) retention time [1]
e.g. detection signal [1]
AVAILABLE
MARKS
[2]
(b)4
[1]
(c)15/28  100 = 53.6%
[2]
2(a) green [1] and blue [1] solids
[2]
(b)(i) iron(II) hydroxide [1]
green [1]
[2]
(ii)Cu(NH3)42+ [1]
deep blue [1]
[2]
(iii) add a solution of barium chloride [1]
white precipitate produced [1]
3(a) it forms the hydrochloride/salt [1]
which is ionic and thus more soluble [1]
[2]
[2]
(b) the phenyl diazonium ion [1]
is unstable at higher temperatures [1]
[2]
(c) iodine reacts with the starch [1]
to produce a blue-black colour [1]
[2]
(d) it contains an ionic group [1]
which is solvated by water [1]
the benzene ring is only a relatively small part of the structure [1]
any 2 from 3
[2]
(e) turn down [1]
the amount of water flowing through the water pump [1]
(f) it removes the ethanoic acid [1]
which has a high/higher boiling point/more difficult to evaporate [1] [2]
(g)
5
[2]
(seal) a capillary tube at one end and put in some azo compound [1]
place in an oil bath/melting point apparatus [1]
heat slowly [1]
note when the solid starts to melt [1]
note when the solid stops melting [1]
[5]
200
8
(h) 5 g of phenylamine = 5/93 = 0.054 mol
7 g of naphthol = 7/144 = 0.0486 = 0.049 mol
RMM of diazo compound is 200.5
0.049 mol = 0.049  200.5 = 9.82 g
% yield = 3/9.82  100 = 30.5498 = 30.5 depending on the numbers presented in the calculation [5] error –[1]
decimal place incorrect –[1]
use of phenylamine –[1]
AVAILABLE
MARKS
[5]
22
4 (a)(i) flask containing water + nitramide [1]
possible mechanism for adding the water/nitramide [1]
means of collecting the nitrous oxide [1]
possible water bath for constant temperature [1]
explanation how the experiment is carried out i.e. measuring volume per unit time [2]
to a maximum of 5 marks
[5]
(ii)temperature
[1]
(iii) e.g. there are too many bubbles to count/not all the bubbles are the same size [1]
(iv) lone pair on the nitrogen (or oxygen) [1]
forms hydrogen bonds [1]
[2]
(b)(i) the point at 1500 seconds [1]
the volume should be 16.8 cm3 [1]
[2]
(ii) 11.2/24000 = 0.00047 = 0.0005 mol of N2O;
hence % decomposed = 0.0005/0.05  100 = 1% [3]
(iii)5  10–6 mol dm–3 s–1 = k  0.5 mol dm–3 k = 10–5 [1]
s–1 [1]
[2]
(c) (i) step one involves the separation of a positive charge from a negative charge which takes energy; a negative ion produced from a negative ion involves repulsion. Hence step one is rate determining [2]
or nitramide is the only reactant in the rate equation
(ii) the reactive intermediate is NO2NH– [1]
(iii) the reactive intermediate needs to be formed in step 1 [1]
then it needs to be used up in step 2 [1]
(d) (i) heat with sodium hydroxide solution [1]
test gas given off with conc hydrochloric acid[1]
white smoke [1]
(ii) heat with alkali, ammonium salt produces ammonia 201
[2]
[3]
[1]
25
Total for Booklet B
60
BLANK PAGE
202
© CCEA 2016