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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
Commentary on candidate 3 evidence (W)
The evidence for this candidate has achieved the following marks for each question of this course
assessment component.
Question 1(a)
The candidate was awarded 0 marks because they have stated that 'more particles have sufficient
energy to collide and form reactants'. The use of the term ‘reactants’ is incorrect – the candidate should
have referred to products.
Question 1(b)(i)
The candidate was awarded 1 mark because a gas syringe is clearly drawn with a scale and labelled.
Incorrect spelling accepted (see general marking instruction (h)).
Question 1(b)(ii)
The candidate was awarded 1 mark because they correctly calculated the volume strength.
Question 1(c)
The candidate was awarded 1 mark because the value of 0.125 next to the graph is considered to be
the value read from the graph by the candidate. The correct final answer (8) is given with correct units.
Question 2(a)(i)
The candidate was awarded 1 mark because they have correctly identified increasing number of
protons, increasing nuclear charge and greater pull (from the nucleus) to the electrons. Any one of
these would be sufficient to award the mark.
Question 2(a)(ii)
The candidate was awarded 0 marks because they have not stated that the atom loses an electron (to
form an ion) or that the number of electron shells is less in the ion than the atom.
Question 2(b)(i)
The candidate was awarded 0 marks because they mentioned shielding, but failed to state that it
increases going down the group.
Question 2(b)(ii)
The candidate was awarded 2 marks because they have identified that the second electron is removed
from a stable shell (1 mark) and that it experiences less shielding. The statement that ' the electron will
experience greater nuclear charge pulling it towards the nucleus' refers to nuclear attraction (1 mark
awarded).
Question 2(c)(i)
The candidate was awarded 0 marks because their predicted lattice enthalpy value of 708 lies outwith
acceptable range (between 720 and 770).
Question 2(c)(ii)
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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
The candidate was awarded 1 mark because the statement given by the candidate –‘the greater the
ionic radii, the smaller the lattice enthalpy’ is correct.
Question 3(a)
The candidate was awarded 1 mark because they identified the bonding and structure correctly.
Question 3(b)
The candidate was awarded 2 marks because the calculation is numerically correct.
Question 3(c)
The candidate was awarded 1 mark because they have drawn a correct structural formula.
Question 4
The candidate was awarded 1 mark because this was considered to be a limited answer. The
candidate has stated that the 'alcohol with the higher boiling point has the stronger intermolecular
forces and is therefore higher viscosity'. An attempt has been made to describe an experimental
procedure and justify the choice of alcohols. However, stating that ethan-1,2-diol and butan-1-ol have
the same number of carbons shows limited understanding.
Question 5a
The candidate was awarded 1 mark for correct product.
Question 5b(i)
The candidate was awarded 1 mark for correctly identifying the correct class of fatty acid.
Question 5b(ii)
The candidate was awarded 1 mark because the systematic name was correct.
Question 5c(i)
The candidate was awarded 1 mark because they did mention that the more unsaturated oil will require
more bromine (1 mark). Colour change is stated (turns blue-black). This is incorrect, so no second
mark awarded.
Question 5c(ii)
The candidate was awarded 1 mark because the ‘non-polar ‘ is taken as referring to hexane, since
hexane is the subject of the question. This is acceptable.
Question 5c(iii)
The candidate was awarded 1 mark because they have stated that coconut has stronger intermolecular
forces. There is no mention of structure or packing of molecules.
Question 6(a)
The candidate was awarded 1 mark because they have correctly identified that the type of peptide is a
hexapeptide.
Question 6(b)
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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
The candidate was awarded 1 mark because the amino acid sequence is correct.
Question 6(c)
The candidate was awarded 0 marks because they have incorrectly stated that the term is ‘Amides’.
Essential is the only acceptable answer.
Question 6(d)(i)
The candidate was awarded 1 mark because, although the candidate refers to peptides instead of
amino acids, this is accepted.
Question 6(d)(ii)
The candidate was awarded 1 mark because the spot circled is incorrect.
Question 6(e)(i)
The candidate was awarded 1 mark because the candidate has drawn an acceptable amino acid
structure. The amino and acid functional groups have been correctly drawn. (The bond from the central
carbon to the methyl group has been drawn to a hydrogen rather than the carbon atom, this is
accepted.)
Question 6(e) (ii)
The candidate was awarded 0 marks because the candidate's answer is incorrect. The working is
unclear in terms of what is being worked out so the mark for units cannot be awarded.
Question 7(a)
The candidate was awarded 0 marks because although the candidate has correctly stated that UV rays
damage the skin, this is negated by the candidate's suggestion that 'sunblock provides free radicals,
which stop the UV rays damaging the skin'.
Question 7(b)(i)
The candidate was awarded 0 marks because the candidate has not stated that a free radical is an
atom or molecule with an unpaired electron.
Question 7(b)(ii)
The candidate was awarded 1 mark because the term ‘initiation’ is correct.
Question 7(b)(iii)
The candidate was awarded 1 mark because the functional group is correctly named.
Question 7(b)(iv)
The candidate was awarded 1 mark because they have given a correct definition of a secondary
alcohol.
Question 7(c)(i)
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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
The candidate was awarded 0 marks because the structure given is incorrect. The candidate has
drawn ethyl butanoate, rather than butyl ethanoate.
Question 7(c)(ii)
The candidate was awarded 0 marks because they have not explained or made mention of gases
being turned to liquid.
Question 7(c)(iii)
The candidate was awarded 2 marks because their answer was correct.
Question 7(c)(iv)
The candidate was awarded 1 mark because the correct type of reaction was stated.
Question 8(a)
The candidate was awarded 0 marks because both temperature conditions and pressure conditions
was identified incorrectly.
Question 8(b)(i)
The candidate was awarded 1 mark because the structure for 2-methylpropene was correctly drawn.
Question 8(b)(ii)
The candidate was awarded 0 marks because the candidate has incorrectly stated that all of the
reactants are turned into the desired products. The answer should say product (singular) as only one
product is made in this reaction.
Question 8(c)
The candidate was awarded 1 mark because all five of the relevant bond enthalpies have been
retrieved from the data book. The second mark was not awarded as the candidate has stated the final
answer as -56 kJ mol-1 rather than +56 kJ mol -1.
Question 9a(i)
The candidate was awarded 2 marks because the candidate has calculated
answer of 4.85 kJ is correct for this temperature change.
T as 11.6
Their final
Question 9a(ii)
The candidate was awarded 1 mark because the candidate has correctly stated that polystyrene does
not conduct heat.
Question 9a(iii)
The candidate was awarded 1 mark because the energy calculation was correct.
Question 9b
The candidate was awarded 2 marks because the Hess’ Law energy calculation was correct.
Question 10
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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
The candidate was awarded 1 mark because they have demonstrated limited understanding of the
chemistry involved. There is mention of using cheap or free raw materials (air and water) to lower costs
and reuse or sale of by-products. Some statements made are at a level below Higher.
Question 11(a)(i)
The candidate was awarded 1 mark because their drawing of flask has a long neck and single
gradation mark.
Question 11(a)(ii)
The candidate was awarded 1 mark because they have made mention of a pipette being used. This
would allow volume to be measured accurately. (No mention of how to use this for accurate volume
measurement.)
Question 11(a)(iii)
The candidate was awarded 2 marks for correct plotting of all points within tolerance and best fit line
drawn.
Question 11(a)(iv)A
The candidate was awarded 0 marks because of the lack of detail in their answer; no mention of
density, mass or volume.
Question 11(a)(iv)B
The candidate was awarded 1 mark for the correct calculation of the percentage of sugar.
Question 11(a)(v)
The candidate was awarded 1 mark for the correct calculation of the mass of sugar.
Question 11(b)(i)
The candidate was awarded 1 mark because they have drawn an aldehyde functional group. (Scoring
out is taken as a correction.)
Question 11(b)(ii)
The candidate was awarded 0 marks because the candidate response is incorrect. The ion electron
equation has not been correctly stated.
Question 11(b)(iii)
The candidate was awarded 0 marks because the colour change stated (brick red--> blue/green) is
incorrect.
Question 11(b)(iv)
The candidate was awarded 3 marks because they have correctly paired the volumes and
concentrations (1 mark) and they have correctly applied the mole ratio (1 mark ) and their final rounded
answer given (0.01) is correct. (1 mark ) .
.
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Higher Chemistry
Question Paper 2016
Commentary - Candidate 3
Question 12(a)(i)
The candidate was awarded 0 marks because they have incorrectly stated permanent dipole to
permanent dipole. The correct answer is hydrogen bonding.
Question 12(a)(ii)
The candidate was awarded 1 mark because the candidate has correctly identified the relationship
between the position of the ester link in the molecule and boiling point. Mention of =O is sufficient (1
mark). The candidate has incorrectly described the relationship between number of branches and
boiling point so the second mark is not awarded.
Question 12(a)(iii)
The candidate was awarded 1 mark because the predicted boiling point was within the accepted
temperature range.
Question 12(b)(i)
The candidate was awarded 1 mark for correct labelling of the peaks.
Question 12(b)(ii)
The candidate was awarded 1 mark because the number of peaks identified (5) was correct.
Total number of marks 51
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