A Levels Chemistry (9701)•9701/13/M/J/19
Explanation
Esterification forms esters from carboxylic acids and alcohols Steps:
- Parse the ester formula CH3COOCH3: acyl group CH3COO- from ethanoic acid (CH3COOH), alkyl group CH3- from methanol (CH3OH).
- Recall general reaction: RCOOH + R'OH → RCOOR' + H2O (esterification).
- Match required reactants: CH3COOH (ethanoic acid) + CH3OH (methanol).
- Compare to options: no pair matches ethanoic acid and methanol.
Why none are correct:
- Overall: The ester CH3COOCH3 requires ethanoic acid and methanol; no option provides this combination.
Why A is wrong:
- Forms CH3COOCH2CH3 (ethyl ethanoate) due to ethanol's C2H5 group.
Why B is wrong:
- Forms CH3CH2COOCH3 (methyl propanoate) due to propanoic acid's C2H5CO group.
Why C is wrong:
- Forms CH3CH2COOCH2CH3 (ethyl propanoate) from both C2H5 groups.
Why D is wrong:
- Forms HCOOCH2CH2CH3 (propyl methanoate) from methanoic acid's HCO and propan-1-ol's C3H7.
Final answer: None
Topic: Carboxylic acids and derivatives
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