A Levels Chemistry (9701)•9701/12/M/J/20
Explanation
Basic Hydrolysis of Esters (Saponification) Steps:
- Identify the ester: CH3CO2CH2CH3 is ethyl acetate, with CH3COO- as the acyl part and CH3CH2O- as the alkyl part.
- Recognize the reaction: Aqueous NaOH causes saponification, breaking the ester bond via nucleophilic attack by OH-.
- Determine products: The acyl part forms the sodium carboxylate salt (CH3CO2Na), and the alkyl part forms the alcohol (CH3CH2OH).
- Confirm conditions: Base hydrolysis yields salt and alcohol, not carboxylic acid.
Why B is correct:
- CH3CO2Na is the sodium acetate formed, as Na+ pairs with the carboxylate ion per salt formation in basic conditions.
Why the others are wrong:
- A: CH3CO2H forms only in acidic hydrolysis, not basic.
- C: CH3CH2OH is a product but not the only one; question asks for products (plural).
- D: CH3CH2ONa would form if the alcohol were deprotonated, but it remains neutral under these conditions.
Final answer: B and C
Topic: Carboxylic acids and derivatives
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