Chemistry · May / June 2025 · Paper 12 · Question 36

The diagram shows the structure of a compound called ethanoic anhydride. 1 mol of ethanoic anhydride reacts with water to form 2 mol of a carboxylic acid only. This carboxylic acid reacts with ethanol to form an ester. How many moles of water react with 1 mol of the ethanoic anhydride and what is the structure of the ester?

1. Anumber of moles of water: 1; structure of the ester: CH3-CO-O-CH2-CH3
2. Bnumber of moles of water: 1; structure of the ester: CH3-CH2-CO-O-CH3
3. Cnumber of moles of water: 2; structure of the ester: CH3-CO-O-CH2-CH3
4. Dnumber of moles of water: 2; structure of the ester: CH3-CH2-CO-O-CH3

As printed in the paper