OCR A-Level Chemistry Synthesis and analytical techniques (02), November 2020: Question 14

1 mark · Medium difficulty · Multiple Choice

Identify which of the given reactions produce propan-1-ol.

Practise this question

Question

Multiple choice question 14 asking which of three reactions (1. alkaline hydrolysis of 1-chloropropane, 2. acid hydrolysis of propyl methanoate, 3. acid hydrolysis of propanenitrile) produce propan-1-ol, with options A (1, 2 and 3), B (Only 1 and 2), C (Only 2 and 3), and D (Only 1).
Question text

14 Which of the following reactions produce propan-1-ol?

1 The alkaline hydrolysis of 1-chloropropane.

2 The acid hydrolysis of propyl methanoate.

3 The acid hydrolysis of propanenitrile.

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1

Your answer

[1]

Mark scheme

Show the mark scheme The mark scheme table shows question number 14 with the correct answer B.

14 B 1 2.3

How to answer it

Synthesising Propan-1-ol

What this question tests

This multiple-choice question assesses your knowledge of organic functional group interconversions, specifically the synthesis of primary alcohols via haloalkane hydrolysis, ester hydrolysis, and nitrile hydrolysis. You must track carbon chain lengths and recognise the reaction products of different organic functional groups.

Question 14 — Multiple Choice

Analyzing the Statements

Statement 1: Alkaline hydrolysis of 1-chloropropane

Result: CH₃CH₂CH₂Cl + OH⁻ → CH₃CH₂CH₂OH + Cl⁻

This is a nucleophilic substitution reaction of a 1-haloalkane using aqueous sodium hydroxide. It retains the 3-carbon chain length and successfully yields propan-1-ol.

Statement 2: Acid hydrolysis of propyl methanoate

Result: Propyl methanoate is an ester made from methanoic acid ( HCOOH ) and propan-1-ol ( CH₃CH₂CH₂OH ).

Hydrolysis of this ester splits it back into its constituent carboxylic acid and alcohol, yielding propan-1-ol and methanoic acid.

Statement 3: Acid hydrolysis of propanenitrile

Result: CH₃CH₂CN + 2H₂O + HCl → CH₃CH₂COOH + NH₄Cl

Nitriles hydrolyse under acidic (or alkaline) conditions to form carboxylic acids (propanoic acid), not primary alcohols. Reduction of a nitrile with LiAlH₄ or H₂ / Ni would produce an amine, not an alcohol. Therefore, statement 3 is incorrect.

Final Answer & Examiner Insight

✅ Correct Option: B (Only 1 and 2)

Since statements 1 and 2 produce propan-1-ol, while statement 3 yields propanoic acid, option B is the correct selection.

🧠 Exam Technique

For multiple-choice questions involving multiple numbered statements, check the easiest statements first to quickly eliminate options. Recognising immediately that statement 3 forms a carboxylic acid (increasing or keeping the carbon count depending on the nitrile, but definitely forming a carboxylic acid group -COOH ) lets you eliminate options A and C instantly.

Mark Scheme Allocation: 1 mark for selecting B. (Specification reference: 2.3 Organic Synthesis).

Topics

Module 4: Core organic chemistry · Module 6: Organic chemistry and analysis · 4.2 Alcohols, haloalkanes and analysis · 6.1 Aromatic compounds, carbonyls and acids · 6.2 Nitrogen compounds, polymers and synthesis

Question and mark scheme from the OCR A-Level Chemistry examination, Synthesis and analytical techniques (02), November 2020. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.