# Ethanoic acid is a carboxylic acid that reacts with ethanol in the presence of an acid catalyst to form a sweet-smelling ester. Describe what happens when ethanoic acid reacts with ethanol to form an ester, and explain why esters are useful.

> Eduqas A-Level Chemistry — 4.5 Carboxylic acids and their derivatives · Describe · 5 marks

> Ethanoic acid has the functional group –COOH. When mixed with ethanol and a few drops of concentrated sulfuric acid, a new compound with a pleasant smell is formed.

## Mark scheme (5 marks)

1. The reaction between a carboxylic acid and an alcohol is called esterification
2. Water is also produced / eliminated in the reaction (alongside the ester)
3. An acid catalyst (concentrated sulfuric acid) is needed / used to speed up the reaction
4. Esters are used as flavourings or in perfumes / cosmetics because they have pleasant / sweet smells
5. Esters are used as solvents (e.g. in paints, varnishes, or nail polish remover)

## Key terms

- [ester](https://www.gradenine.co.uk/glossary/ester)
- [carboxylic acid](https://www.gradenine.co.uk/glossary/carboxylic-acid)
- [catalyst](https://www.gradenine.co.uk/glossary/catalyst)

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Source: [GradeNine](https://www.gradenine.co.uk/q/ethanoic-acid-is-a-carboxylic-acid-a243a29b) · Published by Druglandscape Ltd.