Multiple Choice Questions (MCQ) topic quiz
6.1 Aromatic compounds, carbonyls and acids
Instructions and answers for teachers
These instructions cover the learner activity section which can be found on page 10. This Lesson Element supports OCR A Level Chemistry A.
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.
The Activity
This Lesson Element is a teaching and learning resource containing 10 multiple choice questions (MCQs) on the theme of aromatic compounds, carbonyls and acids. 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.
Learning Outcomes
This lesson element relates to the specification learning outcomes 6.1.1(b), 6.1.1(d), 6.1.1(e), 6.1.1(g), 6.1.1(h), 6.1.1(i), 6.1.1(j), 6.1.1(k), 6.1.2(b), 6.1.2(d), 6.1.2(e), 6.1.3(a), 6.1.3(c), 6.1.3(f)
Introduction
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:
6.1 Aromatic compounds, carbonyls and acids
Version 2 9 © OCR 2016
Multiple Choice Questions (MCQ) topic quiz – answers
1. Which is not evidence used to support the delocalisation model for benzene?
B / Benzene does not undergo electrophilic addition with hydrogen bromide. / Incorrect, benzene resists electrophilic addition reactions. They may have remembered this as ‘benzene does not decolorise bromine water’, and not applied the understanding. /
C / Benzene shows IR absorption at around 3000 cm–1. / Correct answer: This is true for all hydrocarbons as this corresponds to the region for the C–H absorption. It does not support any particular model for benzene. /
D / The hydrogenation of benzene produces less energy than expected. / Incorrect, the delocalised ring requires more energy to break, so hydration is less exothermic. There may be confusion around exothermic reactions, relating to the sign for the enthalpy change etc. /
Your answer
2. Which aromatic substitution does not require a halogen carrier?
B / C6H6 ® C6H5Cl / A halogen carrier is required for halogenation; they may have misread the question. /
C / C6H6 ® C6H5CH3 / They may have forgotten the need for a halogen carrier in the Friedel–Crafts reaction. /
D / C6H6 ® C6H5COCH3 / They may have forgotten the need for a halogen carrier in the Friedel–Crafts reaction. /
Your answer
3. The reaction mechanism shown below is incomplete.
What would be a correct addition to this mechanism?
A / a curly arrow from Cl+ to the benzene ring / Incorrect, the arrow should go from the ring to the Cl+. /B / a curly arrow from the displayed C–H bond, into the ring, in the intermediate / Correct answer /
C / an aromatic ring in the C6 ring in the intermediate / Incorrect, only a partial ring with a positive charge exists in the intermediate. /
D / HCl as a product in the final step / Incorrect, H+ is the product. /
Your answer
4. Which statement best explains the solubility of carboxylic acids?
B / The oxygen atoms in COOH have lots of electrons, forming strong London forces with water. / There are indeed London forces involved, but these are far less important than other intermolecular interactions. /
C / Carboxylate ions form in water, which are highly soluble in the polar solvent. / As carboxylic acids are weak acids few carboxylate ions are formed, so the intermolecular interactions are more significant. /
D / The oxygen atoms can form hydrogen bonds with the water molecules. / Correct answer /
Your answer
5. Which will not result in a reaction?
B / C6H5OH + NaOH / Incorrect, sodium phenoxide will form. /
C / C6H5OH + Na2CO3 / Correct answer: Phenol will not react with carbonates. /
D / C6H5OH + HNO3/H2SO4 / Incorrect, this will result in nitration of the benzene ring. /
Your answer
6. Which is the correct product formed from the bromination of nitrobenzene?
B / / Correct answer: electron withdrawing groups like NO2 direct groups to position 3 /
C / / Incorrect, electron donating groups like OH or NH2 direct to position 2 and 4 /
D / / They have confused this with the reaction of phenol with bromine. /
Your answer
7. Which set of reactants and conditions would form the substance below?
B / 1-Hydroxyheptamine and NaBH4 / Incorrect, neither the alcohol nor the amine can be reduced by NaBH4. /
C / 4,5-Dimethylheptanal and NaCN(aq)/H+(aq) / Correct answer: A hydroxynitrile can be formed from an aldehyde and HCN. /
D / 5,6-Dimethyloctanenitrile and NaOH(aq)/reflux / Incorrect, a hydroxide cannot attach to a chain this way. /
Your answer
8. Which substance would test positively with 2,4-DNP but negatively with Tollens’ reagent?
A / Propanal / Incorrect; it is possible they have remembered the Tollens’ the wrong way round. /B / Propan-1-ol / This would not react with either as it has no carbonyl group. /
C / Propanoic acid / Incorrect, learners often think that the carbonyl group in an acid can react with 2,4-DNP. /
D / Propanone / Correct answer /
Your answer
9. Sulfonation of benzene involves an electrophilic substitution mechanism.
What would be the final product?
A / / Incorrect, this is the molecule in the intermediate step having lost an H+. /B / / Correct answer /
C / / Incorrect, the arrow is moving to the H not back toward the sulfur. /
D / / Incorrect, there are no arrows to show a S–O bond breaking. /
Your answer
10. Which of the following substances will react with ethanol to make ethyl ethanoate?
2. / /
3. / /
A / 1, 2 and 3 / Correct answer /
B / only 1 and 2 / A common mistake, many learners forget about anhydrides as they are involved in few reactions. /
C / only 2 and 3 / Incorrect /
D / only 1 / The learner may have only remembered acids as chemicals which can form esters. /
Your answer
Version 2 9 © OCR 2016
Multiple Choice Questions (MCQ) topic quiz
6.1 Aromatic compounds, carbonyls and acids
Learner Activity
1. Which is not evidence used to support the delocalisation model for benzene?
B / Benzene does not undergo electrophilic addition with hydrogen bromide. /
C / Benzene shows IR absorption at around 3000 cm–1. /
D / The hydrogenation of benzene produces less energy than expected. /
Your answer
2. Which aromatic substitution does not require a halogen carrier?
B / C6H6 ® C6H5Cl /
C / C6H6 ® C6H5CH3 /
D / C6H6 ® C6H5COCH3 /
Your answer
Version 2 10 © OCR 2016
3. The reaction mechanism shown below is incomplete.
What would be a correct addition to this mechanism?
A / a curly arrow from Cl+ to the benzene ring /B / a curly arrow from the displayed C–H bond, into the ring, in the intermediate /
C / an aromatic ring in the C6 ring in the intermediate /
D / HCl as a product in the final step /
Your answer
4. Which statement best explains the solubility of carboxylic acids?
B / The oxygen atoms in COOH have lots of electrons, forming strong London forces with water. /
C / Carboxylate ions form in water, which are highly soluble in the polar solvent. /
D / The oxygen atoms can form hydrogen bonds with the water molecules. /
Your answer
5. Which will not result in a reaction?
A / C6H5OH + Br2 /B / C6H5OH + NaOH /
C / C6H5OH + Na2CO3 /
D / C6H5OH + HNO3/H2SO4 /
Your answer
6. Which is the correct product formed from the bromination of nitrobenzene?
A / / B / /C / / D / /
Your answer
7. Which set of reactants and conditions would form the substance below?
B / 1-Hydroxyheptamine and NaBH4 /
C / 4,5-Dimethylheptanal and NaCN(aq)/H+(aq) /
D / 5,6-Dimethyloctanenitrile and NaOH(aq)/reflux /
Your answer
8. Which substance would test positively with 2,4-DNP but negatively with Tollens’ reagent?
B / Propan-1-ol /
C / Propanoic acid /
D / Propanone /
Your answer
9. Sulfonation of benzene involves an electrophilic substitution mechanism.
What would be the final product?
A / /B / /
C / /
D / /
Your answer
10. Which of the following substances will react with ethanol to make ethyl ethanoate?
2. / /
3. / /
A / 1, 2 and 3 /
B / only 1 and 2 /
C / only 2 and 3 /
D / only 1 /
Your answer
Version 2 10 © OCR 2016