These instructions cover the learner activity section which can be found on page 10 . This
Lesson Element supports OCR AS and A Level Chemistry B (Salters).
When distributing the activity section to the learners either as a printed copy or as a
Word file you will need to remove the teacher instructions section.
This Lesson Element is a teaching and learning resource containing 10 multiple choice questions (MCQs) on the theme of what’s in a medicine. Some questions might require synoptic thinking, using knowledge and ideas from various topics across the full A Level content.
This resource can be used to test and consolidate understanding at the end of a topic or to revisit and refresh knowledge at a later point in the course.
This lesson element relates to the specification learning outcomes WM(b), WM(c), WM(d),
WM(e), WM(h), WM(i), WM(j).
Multiple choice questions allow rapid coverage of a wide range of sub-topics.
Contrary to a widespread belief among students, multiple choice questions are not necessarily easy – they can be easy, moderate or difficult.
The questions are written so that the incorrect answers are plausible distractors based on common errors or misconceptions.
The questions in this quiz cover topics mainly from specification sections:
What’s in a medicine?
Version 1 1 © OCR 2016

1. The formation of ethene from the dehydration of ethanol can best be described as:
A an addition reaction The reverse process is an addition reaction; the learner may have confused reactants and products.
B
C
D an elimination reaction an oxidation reaction a substitution reaction
Correct answer : Water is eliminated from the ethanol molecule.
The learner may have associated ethanol with oxidation reactions.
The learner may have made the association with substitution reactions as ethanol is the reactant.
Your answer B
2. Which of these compounds is a secondary alcohol?
A ethane-1,2-diol The learner may be associating the term ‘diol’ with a secondary alcohol.
B 2-methylpentan-3-ol
C 2-methylpentan-2-ol
D methylpropan-1-ol
Correct answer: The –OH group is attached to a carbon in the 3 position, which is attached to two carbons.
This is a common error as the learner has linked the –OH group being in the 2 position with it being a secondary alcohol, whereas in fact it is tertiary.
This is a primary alcohol.
Your answer B
Version 1 2 © OCR 2016

3. Which of these compounds could be oxidised to produce a carboxylic acid?
A CH
3
CH
2
CH
3
The learner does not understand the oxidation process if they have chosen a molecule that does not contain oxygen.
B CH
3
CH
2
(OH)CH
2
CH
3
This is a secondary alcohol; the learner may be answering the first part of the question
(can be oxidised) without considering the second part.
C
D
CH
(CH
3
CHO
3
)
2
C(OH)CH
2
CH
3
Correct answer: Ethanal can be further oxidised to ethanoic acid.
This is a tertiary alcohol and cannot be oxidised at all.
Your answer C
4. A compound has the empirical formula CH
2
O. A mass spectrum of the compound features a molecular ion peak with an m/z ratio of 60. The infrared spectrum of the compound has no peaks above 3 000 cm –1
.
What is the name of the compound?
A ethanal
B
C
D ethanoic acid ethyl ethanoate methyl methanoate
The learner has seen the empirical formula and associated it with the aldehyde functional group, even though this does not fit with the molecular formula.
This does fit the molecular formula, but is contradicted by absence of an O
–H peak in the infrared spectrum.
The learner has correctly identified an ester, but has too many carbon atoms to fit the molecular mass or empirical formula.
Correct answer: The compound has the molecular formula C
2
H
4
O
2
but is not a carboxylic acid or alcohol, so must be an ester.
Your answer D
Version 1 3 © OCR 2016

5. The mass spectrum of an organic compound sometimes contains a signal at one m/z unit higher than the molecular ion. Why is this?
A It is due to the presence of one atom of 2 H.
Although this would result in an m/z ratio one higher than the M r
, the extremely low abundance of deuterium would make this peak all but invisible on this scale.
B It is due to the association of a H atom to the molecular ion.
This would result in a higher m/z ratio but is chemically extremely unlikely.
C It is due to the presence of one atom of 13 C.
D It is due to removal of two electrons at the ionisation stage.
Correct answer : This peak becomes more noticeable as the size of the molecule increases and the chance of a 13 C atom being incorporated increases.
While the removal of an extra electron can occur in the mass spectrometer, it would in fact result in a peak at half the molecular mass.
Your answer C
Version 1 4 © OCR 2016

6. Naturally occurring chlorine exists as two abundant isotopes.
How many molecular ion peaks would one expect to see in the mass spectrum of chloroform, CC l
3
H?
A 1 The learner has failed to appreciate that the existence of isotopes with similar abundance will result in more than one molecular ion peak.
B 2
C 3
The learner has assumed one peak for each isotope, without appreciating that there is more than one chlorine atom in the molecule.
The learner has assumed one peak for each chlorine atom, without appreciating the number of different combinations that could be present.
D 4 Correct answer : Three atoms of chlorine, each having two possible isotopic masses, results in four different combinations of 35 C l and 37 C l
.
Your answer D
Version 1 5 © OCR 2016

7. A mixture of propan-1-ol and methanoic acid is refluxed in the presence of concentrated sulfuric acid.
Which statement is true for this reaction?
A The ester formed is called propyl methanoate.
Correct answer : The ester formed would be called propyl methanoate.
B It is an irreversible reaction. This is a reversible reaction, although the conditions of concentrated acid do help to force the equilibrium position further to the right hand side.
C The mixture turns from orange to green.
The learner is confusing esterification with oxidation.
D Hydrogen chloride is also formed. Hydrogen chloride would be formed in the reaction of an acyl chloride and alcohol but in this reaction the by-product is water.
Your answer A
Version 1 6 © OCR 2016

8. A student wants to carry out the preparation of an ester, propyl ethanoate, under acidic conditions. The balanced equation for the reaction is shown below.
CH
3
COOH(aq) + CH
3
CH
2
CH
2
OH(aq) H
2
O(l) + CH
3
COOCH
2
CH
2
CH
3
The student carries out some tests on the reaction mixture and decides that the reaction had not gone to completion.
Which result provides proof that this is the case?
A The presence of a sharp peak around 1700 cm –1
on the infrared.
This peak merely confirms the presence of a
C=O bond and will be present at any stage in the reaction.
B The presence of a single spot on a thin layer chromatography plate.
This would be evidence that the reaction had gone to completion, as only the ester would be visible in the reaction mixture.
C The presence of three spots on a thin layer chromatography plate.
Correct answer : The presence of three spots shows that some ester has been produced but that the two reagents are still present in the reaction mixture.
D The presence of a peak on the mass spectrum with an m/z ratio of 59.
This peak could occur as a fragment whether the ester has been formed or not (it represents the CH
3
COO + ion).
Your answer C
Version 1 7 © OCR 2016

9. The alcohol butan-1-ol is heated with acidified sodium dichromate and the product distilled directly from the reaction mixture.
Which statement is not true of the reaction?
A The product is called butanal. This is the correct name for the product – the learner may have thought the product was butanoic acid.
B The product cannot be oxidised any further.
Correct answer : This is not true as the aldehyde can be further oxidised to a carboxylic acid.
C The product has a lower boiling point than the original alcohol.
D The reaction mixture will change from orange to green.
This is true, and the reason that the product can be separated by distillation. The candidate may be thinking of butanoic acid again.
The reaction mixture would change as the butan-1-ol is able to reduce the dichromate( VI ) ion
– the learner may think that there is not a colour change during partial oxidation of the alcohol.
Your answer B
Version 1 8 © OCR 2016

10. Which of the following statements is/are true for 4-hydroxybenzoic acid, a precursor for the manufacture of aspirin?
1. The infrared spectrum will contain a broad peak at around 3000 cm –1
and a sharp peak at around 1700   cm
–1
.
2. The compound will turn purple in the presence of iron( III ) chloride.
3. The compound will react with ethanoic anhydride to form an ester.
A 1, 2 and 3 Correct answer : The compound contains a phenol and a carboxylic acid group.
B
C
D only 1 and 2 only 2 and 3 only 1
The candidate has not correctly identified that the phenol group will react with an acid anhydride.
The candidate has not correctly identified the presence of the –OH and C=O peaks in the
IR spectrum.
The candidate has not correctly identified either the positive test for phenol or its ability to react with an acid anhydride.
Your answer A
This resource has been produced as part of our free Chemistry teaching and learning support package. All the Chemistry teaching and learning resources, including delivery guides, topic exploration packs, lesson elements and more are available on the qualification webpages.
If you are looking for examination practice materials, you can find Sample Assessment Materials (SAMs) and a link to the Practice
Papers on the qualification webpages: Chemistry A , Chemistry B .
We’d like to know your view on the resources we produce. By clicking on ‘
Like
’ or ‘
Dislike
’ you can help us to ensure that our resources work for you. When the email template pops up please add additional comments if you wish and then just click ‘Send’. Thank you.
If you do not currently offer this OCR qualification but would like to do so, please complete the Expression of Interest Form which can be found here: www.ocr.org.uk/expression-of-interest
OCR Resources : the small print
OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board, and the decision to use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or omissions within these resources.
© OCR 2016 - This resource may be freely copied and distributed, as long as the OCR logo and this message remain intact and OCR is acknowledged as the originator of this work.
OCR acknowledges the use of the following content: n/a
Please get in touch if you want to discuss the accessibility of resources we offer to support delivery of our qualifications: resources.feedback@ocr.org.uk
Version 1 9 © OCR 2016

1. The formation of ethene from the dehydration of ethanol can best be described as:
A an addition reaction
B an elimination reaction
C an oxidation reaction
D a substitution reaction
2. Which of these compounds is a secondary alcohol?
A ethane-1,2-diol
Your answer
B 2-methylpentan-3-ol
C 2-methylpentan-2-ol
D methylpropan-1-ol
Your answer
3. Which of these compounds could be oxidised to produce a carboxylic acid?
A CH
3
CH
2
CH
3
B CH
3
CH
2
(OH)CH
2
CH
3
C CH
3
CHO
D (CH
3
)
2
C(OH)CH
2
CH
3
Your answer
10 © OCR 2016 Version 1

4. A compound has the empirical formula CH
2
O. A mass spectrum of the compound features a molecular ion peak with an m/z ratio of 60. The infrared spectrum of the compound has no peaks above 3000 cm –1
.
What is the name of the compound?
A ethanal
B ethanoic acid
C ethyl ethanoate
D methyl methanoate
Your answer
5. The mass spectrum of an organic compound sometimes contains a signal at one m/z unit higher than the molecular ion. Why is this?
A It is due to the presence of one atom of 2 H.
B It is due to the association of a H atom to the molecular ion.
C It is due to the presence of one atom of 13 C.
D It is due to removal of two electrons at the ionisation stage.
Your answer
6. Naturally occurring chlorine exists as two abundant isotopes.
How many molecular ion peaks would one expect to see in the mass spectrum of chloroform, CC l
3
H?
A 1
B 2
C 3
D 4
Your answer
Version 1 11 © OCR 2016

7. A mixture of propan-1-ol and methanoic acid is refluxed in the presence of concentrated sulfuric acid.
Which statement is true for this reaction?
A The ester formed is called propyl methanoate.
B It is an irreversible reaction.
C The mixture turns from orange to green.
D Hydrogen chloride is also formed.
Your answer
8. A student wants to carry out the preparation of an ester, propyl ethanoate, under acidic conditions. The balanced equation for the reaction is shown below.
CH
3
COOH(aq) + CH
3
CH
2
CH
2
OH(aq) H
2
O(l) + CH
3
COOCH
2
CH
2
CH
3
The student carries out some tests on the reaction mixture and decides that the reaction had not gone to completion.
Which result provides proof that this is the case?
A The presence of a sharp peak around 1700 cm –1
on the infrared spectrum.
B The presence of a single spot on a thin layer chromatography plate.
C The presence of three spots on a thin layer chromatography plate.
D The presence of a peak on the mass spectrum with an m / z ratio of 59.
Your answer
Version 1 12 © OCR 2016

9. The alcohol butan-1-ol is heated with acidified sodium dichromate and the product distilled directly from the reaction mixture.
Which statement is not true of the reaction?
A The product is called butanal.
B The product cannot be oxidised any further.
C The product has a lower boiling point than the original alcohol.
D The reaction mixture will change from orange to green.
Your answer
10. Which of the following statements is/are true for 4-hydroxybenzoic acid, a precursor for the manufacture of aspirin?
1. The infrared spectrum will contain a broad peak at around 3000 cm –1
and a sharp peak at around 1700 cm –1
.
2. The compound will turn purple in the presence of iron( III ) chloride.
3. The compound will react with ethanoic anhydride to form an ester.
A 1, 2 and 3
B only 1 and 2
C only 2 and 3
D only 1
Your answer
Version 1 13 © OCR 2016