A Levels Chemistry (9701)•9701/11/M/J/22
Explanation
Ester hydrolysis yields carboxylic acid and alcohol Steps:
- Hydrolysis of an ester RCOOR' produces RCOOH and R'OH.
- Ethanoic acid is CH₃COOH, so the acyl group is CH₃C(O)-.
- Butan-2-ol is CH₃CH(OH)CH₂CH₃, so the alkyl group is -CH(CH₃)CH₂CH₃.
- The ester formula is CH₃CO₂CH(CH₃)CH₂CH₃, matching option B.
Why B is correct:
- B is the ester of ethanoic acid and butan-2-ol; by ester hydrolysis definition, it yields CH₃COOH and CH₃CH(OH)CH₂CH₃.
Why the others are wrong:
- A is butan-2-one (ketone); ketones do not undergo hydrolysis to give alcohol and carboxylic acid.
- C is methyl propanoate; hydrolysis gives propanoic acid (CH₃CH₂COOH) and methanol (CH₃OH).
- D is propyl ethanoate; hydrolysis gives ethanoic acid (CH₃COOH) and propan-1-ol (CH₃CH₂CH₂OH).
Final answer: B
Topic: Carboxylic acids and derivatives
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