O-LevelChemistryOrganic Chemistry5070/12 · Oct/Nov 2020 · Q381 Mark

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?

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Anumber of moles of water: 1, structure of the ester: [Diagram shows ethyl ethanoate: CH3COOCH2CH3]

Bnumber of moles of water: 1, structure of the ester: [Diagram shows ethyl ethanoate: CH3COOCH2CH3]

Cnumber of moles of water: 2, structure of the ester: [Diagram shows ethyl ethanoate: CH3COOCH2CH3]

Dnumber of moles of water: 2, structure of the ester: [Diagram shows ethyl ethanoate: CH3COOCH2CH3]

✓ Correct answer

B: number of moles of water: 1, structure of the ester: [Diagram shows ethyl ethanoate: CH3COOCH2CH3]

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Topic: Organic Chemistry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2020 Paper 1 Variant 2, question 38.

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