Multiple choice practice test
Polymers and life
Instructions and answers for teachers
These instructions cover the student activity section which can be found on page 9. This
Lesson Element supports OCR A Level Chemistry B (Salters).
When distributing the activity section to the students either as a printed copy or as a
Word file you will need to remove the teacher instructions section.
The Activity
This Lesson Element contains 10 multiple choice questions on topics covered in the
teaching module Polymers and life.
The question worksheet can be used to consolidate understanding at the end of
teaching the module, to revisit and refresh knowledge at a later point in the course,
or during exam preparation.
Learning Outcomes
This Lesson Element relates to the specification learning outcomes PL(c), PL(f),
PL(i), PL(k), PL(l), PL(m), PL(n), PL(q), PL(s).
Introduction
Multiple choice questions form part of the written assessment in A Level Chemistry B
(Salters). Besides a means of assessing knowledge of content, this question
worksheet therefore also provides useful preparation for the examinations.
The questions are written so that the incorrect answers are plausible distractors
based on common errors or misconceptions. In the Answers section below, guidance
is given on the reason for including each distractor. This information can be used as
a basis for formative feedback, or for the planning of remedial revision sessions.
These questions cover topics from the teaching module Polymers and life.
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Multiple Choice practice test answers
1.
What is the name of the polymer formed from dihexanoyl chloride and
1,4-diaminobutane?
A
nylon-6
The learner has not appreciated that this is a
co-polymer.
B
nylon-4,6
Correct answer: The amine has four
carbons and the acyl chloride has six.
C
nylon-6,4
The learner has confused the order of the
numbers.
D
nylon-6,6
The learner has possibly counted the
nitrogen atoms as part of the numbering
system in 1,4-diaminohexane.
Your answer
2.
Which molecule is a primary amide?
A
CH3CH(NH2)CH3
The learner is confused between a primary
amide and a primary amine.
B
CH3NHCOCH3
This is a secondary amide; the learner may
be confused about the definition of a primary
amide.
C
C6H5CONH2
Correct answer: This is a derivative of a
carboxylic acid with the –OH group replaced
with a NH2 group.
D
CH3NHCH2CH3
This is a secondary amine. The learner may
have simply guessed at something that looks
a little unfamiliar.
Your answer
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B
2
C
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3.
Which statement is true about the structure of a DNA double helix?
A
Adenine pairs with uracil.
Uracil is present in RNA only.
B
Bases are joined in the middle by
condensation reactions.
Bases are joined by hydrogen bonding;
condensation reactions link the nucleotides
together.
C
The backbone is made up of
phosphate and ribose.
Ribose is present in RNA only.
D
The molecule is negatively
charged overall.
Correct answer: The phosphate groups
make the backbone negatively charged,
which aids solubility.
Your answer
4.
D
A student carries out the hydrolysis of an ester, benzyl ethanoate, under acidic
conditions. Some tests were carried out on the reaction mixture and it was decided
that the reaction had not gone to completion.
Which of the results below provides proof that this is the case?
A
A broad peak above 3000 cm–1
on the infrared spectrum.
This indicates the presence of an alcohol but
does not indicate whether or not any
unhydrolysed ester remains in the mixture.
B
Two spots on a thin layer
chromatography plate.
This would confirm that the reaction had gone
to completion as the ester would no longer be
present but the alcohol and carboxylic acids
would be.
C
Three spots on a thin layer
chromatography plate.
Correct answer: This confirms that
unreacted ester is still present alongside the
alcohol and carboxylic acid.
D
A peak on the mass spectrum
with an m/z ratio of 60.
This confirms the presence of ethanoic acid
but this fragment could be present at any
stage.
Your answer
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C
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5.
Which molecule is optically active?
A
B
C
D
A
Two carbons have three other carbons attached; however the molecule is
symmetrical so they are not chiral
B
Correct answer: The carbon with the –OH group attached has three other
groups attached, making it a chiral centre.
C
This molecule is completely planar and cannot have chiral carbons.
D
The learner is perhaps thinking that a carbon on the benzene ring is chiral,
but there are only three groups attached due to the presence of double
bonding.
Your answer
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B
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6.
A compound has the molecular formula C5H10O and the 1H-NMR spectrum contains
four peaks. The compound could be:
A
3-methylbutan-2-one
3-Methylbutan-2-one would have one
environment for the methyl adjacent to the
carbonyl, another for the hydrogen on the
third carbon but the two methyl groups
attached to the end of the chain would be
identical environments due to rotational
symmetry.
B
pentanal
Pentanal would have five different hydrogen
environments. The learner has most likely
forgotten the hydrogen attached to the
aldehyde group.
C
pentan-2-one
Correct answer: One carbon would have a
carbonyl attached; the other four carbons
would each present a different hydrogen
environment since the molecule is not
symmetrical.
D
pentan-3-one
The molecule is symmetrical about the
central carbonyl group and so only two
hydrogen environments exist.
Your answer
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C
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7.
The graph opposite shows the effect of substrate
concentration for an enzyme-catalysed reaction. Which
statement best explains the shape of the graph?
A
The enzymes are denatured at
higher substrate concentrations.
The learner is confused about the meaning of
the term ‘denatured’.
B
The enzyme active sites become
saturated with substrate at higher
concentrations.
Correct answer: At high concentrations the
reaction is zero order with respect to
substrate concentration as the maximum
number of active sites are occupied.
C
The substrate concentration does
not affect rate.
The concentration does affect rate at lower
concentrations; the learner is thinking in
terms of the plateau of the graph only.
D
There is a competitive inhibitor
present in the mixture.
The graph would be the same shape in the
presence of an inhibitor; however the
presence of the inhibitor does not determine
the shape of the graph itself, only the time
taken for the graph to plateau.
Your answer
8.
Which hydrolysis reaction could result in both the organic species being produced as
uncharged molecules?
A
Hydrolysis of an amide under
acidic conditions.
The learner has not appreciated that the
amine molecule would be protonated under
acidic conditions.
B
Hydrolysis of an amide under
alkaline conditions.
The learner has not appreciated that the
carboxylic acid molecule would be
deprotonated under alkaline conditions.
C
Hydrolysis of an ester under
acidic conditions.
Correct answer: Neither the carboxylic acid
nor the alcohol would react with the acid.
D
Hydrolysis of an ester under
alkaline conditions.
The learner has not appreciated that the
carboxylic acid would be deprotonated under
alkaline conditions.
Your answer
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B
6
C
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9.
Which two reagents could be used to prepare the ester propyl ethanoate?
A
ethanoic acid and propan-2-ol
This would produce an isomer of propyl
ethanoate but would not contain a straight
chain propyl group.
B
ethanoic anhydride and
propan-1-ol
Correct answer: This would produce propyl
ethanoate with ethanoate ions as a side
product.
C
ethanoyl chloride and
1-aminopropane
This would produce the amide propyl
ethanamide.
D
propanoic acid and ethanol
The learner is confused about the naming
system for esters as this would produce ethyl
propanoate.
Your answer
10.
B
Which statement(s) is/are true for all naturally occurring amino acids?
Statement 1: They can behave as acids and bases
Statement 2: They rotate the plane of polarised light
Statement 3: They have no net charge when dissolved in water
A
1, 2 and 3
Statement 1 is true. Statement 2 is untrue
because glycine does not have a chiral
centre. Statement 3 is untrue – although the
–NH3+ and –COO– groups of the zwitterion do
cancel out, some amino acids contain acidic
or basic groups in their side chain which are
ionised.
B
only 1 and 2
Statement 2 is untrue (see above) – many
learners forget that the side chain can be a
hydrogen atom.
C
only 2 and 3
Statement 2 is untrue (see above). Statement
3 is untrue but many learners think of the ‘R’
group of amino acids as not containing acidic
or basic groups.
D
only 1
Correct answer: Statement 1 is the only true
statement (see above).
Your answer
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D
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Multiple choice practice test
Polymers and life
Learner Activity
1.
What is the name of the polymer formed from dihexanoyl chloride and
1,4-diaminobutane?
A
nylon-6
B
nylon-4,6
C
nylon-6,4
D
nylon-6,6
Your answer
2.
Which molecule is a primary amide?
A
CH3CH(NH2)CH3
B
CH3NHCOCH3
C
C6H5CONH2
D
CH3NHCH2CH3
Your answer
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Copyright © OCR 2016
3.
Which statement is true about the structure of a DNA double helix?
A
Adenine pairs with uracil.
B
Bases are joined in the middle by condensation reactions.
C
The backbone is made up of phosphate and ribose.
D
The molecule is negatively charged overall.
Your answer
4.
A student carries out the hydrolysis of an ester, benzyl ethanoate, under acidic
conditions. Some tests were carried out on the reaction mixture and it was decided
that the reaction had not gone to completion.
Which of the results below provides proof that this is the case?
A
A broad peak above 3000 cm–1 on the infrared spectrum.
B
Two spots on a thin layer chromatography plate.
C
Three spots on a thin layer chromatography plate.
D
A peak on the mass spectrum with an m/z ratio of 60.
Your answer
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Copyright © OCR 2016
5.
Which molecule is optically active?
A
B
C
D
Your answer
6.
A compound has the molecular formula C5H10O and the 1H-NMR spectrum contains
four peaks. The compound could be:
A
3-methylbutan-2-one
B
pentanal
C
pentan-2-one
D
pentan-3-one
Your answer
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Copyright © OCR 2016
7.
The graph below shows the effect of substrate concentration for an enzymecatalysed reaction.
Which statement best explains the shape of the graph?
A
The enzymes are denatured at higher substrate concentrations.
B
The enzyme active sites become saturated with substrate at higher
concentrations.
C
The substrate concentration does not affect rate.
D
There is a competitive inhibitor present in the mixture.
Your answer
8.
Which hydrolysis reaction could result in both the organic species being produced as
uncharged molecules?
A
Hydrolysis of an amide under acidic conditions.
B
Hydrolysis of an amide under alkaline conditions.
C
Hydrolysis of an ester under acidic conditions.
D
Hydrolysis of an ester under alkaline conditions.
Your answer
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9.
Which two reagents could be used to prepare the ester propyl ethanoate?
A
ethanoic acid and propan-2-ol
B
ethanoic anhydride and propan-1-ol
C
ethanoyl chloride and 1-aminopropane
D
propanoic acid and ethanol
Your answer
10.
Which statement(s) is/are true for all naturally occurring amino acids?
Statement 1: They can behave as acids and bases
Statement 2: They rotate the plane of polarised light
Statement 3: They have no net charge when dissolved in water
A
1, 2 and 3
B
only 1 and 2
C
only 2 and 3
D
only 1
Your answer
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