ADVANCED LEVEL
CHEMISTRY
6031/02
NOVEMBER 2022
EXAMINER REPORT
INTRODUCTION
This report carries information on how candidates performed in Chemistry Paper 2 for
November 2022 at Advanced Level. It reflects an overview of the candidates’ performance on
each question. The information is intended to be applied by stakeholders and candidates in
future.
GENERAL COMMENTS
Incomplete explanations were found on many scripts. In cases where explanations became
longer than necessary, content errors or contradiction of facts became common. Candidates
took state symbols for granted by either ignoring them where they were necessary or writing
wrong state symbols.
QUESTION 1
1 (a) This question required factual recall on behaviour of a beam of particles passing through
an electric field. The majority of candidates could not draw the correct diagram, which required
the particles originating from a source passing between (+) positive polarity and (-) negative
polarity. Direction of particles using arrowheads was also required.
(b) (i) Good candidates correctly gave ionisation as the answer. Candidates who gave
oxidation as the answer were marked correct. However, quite a number of candidates gave
ionisation energy or enthalpy and this was rejected.
(ii) The majority of candidates gave the correct equation without correct states and were
penalised.
(c)(i) Weak candidates gave the ordinary level electronic configuration of the O2- ion.
(ii) A few candidates were able to correctly sketch the graph showing a sudden 'jumb' in
energy between the 8th and 9th electron.
(d) (i) Almost all candidates gave the correct answer as 80 without units. It should be
emphasized that relative atomic mass has no units.
(ii) A large number of candidates did not give low Ks for Agl as the correct answer.
QUESTION 2
2(a) (i) Most candidates did not give correct explanations for the terms order and rate of
reaction Many would give incomplete explanations, others would give equations.
(b)The table proved difficult for most candidates to interpret. Part (i) and (ii) were correctly
answered by many. Part (iii) was done well by a few.
(c) (i) A sizeable number of candidates gave the correct rate equation from orders obtained.
(b) (Ii) Correct species were derived from the rate equation.
(iii) A few candidates explained how the reaction could be monitored by colorimetric
method. It is important to be able to distinguish between colorimetric and calorimetric.
(d) Candidates were expected to realise that maintaining constant volume was a measure to
monitor changes in concentration the moment one substance's volume was halved or doubled.
QUESTION 3
3 (a) Observation was important, majority of candidates failed to recall correct observations
as white flame and white solid. White fumes and white precipitate were considered to be wrong.
(b) (i) Strong candidates gave the correct equation Mg(s) + H2O(g)
MgO(s) + H2(g)
Some candidates gave magnesium hydroxide as an answer, which was wrong.
(ii) Majority of candidates managed to give the correct trend which was decreasing. Others
failed to express the converse.
(iii) Significant numbers of candidates gave a good comparison between Mg (OH)2 and
Ca(OH)2. Magnesium hydroxide is a good anti-acid because it is a weak base whilst calcium
hydroxide is a strong base which is corrosive.
(c) (i) The majority of candidates managed to give the correct bonding and structure.
However some confused bonding and structure. Whilst SiO2 is a giant covalent structure, CO2
is a simple covalent structure. Some candidates gave the shape of the molecule where structure
was required.
(ii) Good answers were given such as making ceramics, making glass, but weird answers were
also given such as, work as flux.
QUESTION 4
4. Most candidates did not perform well in this question. A few candidates scored all the marks.
(a) (i) Quite a number of candidates gave structures of the functional groups instead of
naming as was required. Benzene as functional group was quite popular with candidates and
this was wrong.
(ii) Most candidates did not recognize hydrolysis of an ester in the structure given.
Accepted products were ethanol and the ammonium salt derivative. Hydrolysis of esters was a
major problem to the majority of candidates as was seen by the poor structures given.
(b)(i) The name 4-nitrobenzoic acid did not come up with most candidates. A significant
number of candidates failed to give correct reagents and conditions especially for the one that
involved reduction of nitrobenzene to phenylamine.
QUESTION 5
5. Few candidates managed to score all the marks in this question.
(a) Error involving many was to give structural formulae instead of displayed formulae for
compound A. Giving both cis and trans isomers of compound A was rejected.
(b) (i) Candidates failed to determine structural formulae of the organic products from the
displayed formulae of compound G as it reacted with given substances. Some candidates
understood substitution of -OH group with chlorine atom from thionyl chloride. Good
candidates did rupture the carbon-carbon double bond and complete oxidation of the terminal
-OH to carboxyl group giving a correct structure with hot acidified potassium permanganate.
Candidates are encouraged to recall the structure of 2,4-dinitrophenylhydrazine so as to get the
correct structure when it reacts.
(b) (ii) Good answer was nucleophilic substitution instead of only substitution reaction. The
majority got the mark. However others did give electrophilic substitution as an answer which
was wrong.
(c)Even weak candidates scored a mark on use but failed to identify the reason. Some good
answers were given for example, jewellery was given as the use and the reason was being inert.
QUESTION 6
6 (a) Majority of candidates could not define genetic fingerprinting.
(b) Few candidates managed to score full marks on the question. Important points were DNA
fragment placed near cathode, negatively charged fragments migrate to the anode and are
separated according to size, then bands produced are observed as a pattern.
(c) (i) The question was well done by candidates.
(ii)Most of the candidates failed to state all the three applications of genetic fingerprinting,
some good answers were maternity and paternity test, also identification of GMOs.
CONCLUSION
Genetic fingerprinting and Periodic Trends as topics appeared to have low appreciation
amongst candidates.