# Ethanoic acid is a carboxylic acid used in vinegar. A student adds a small piece of calcium carbonate to a sample of ethanoic acid solution. Describe what the student would observe and explain what is happening, including the products formed in the reaction.

> OCR A-Level Chemistry B: Salters (H433) — 6.1 Aromatic compounds, carbonyls and acids · Describe · 5 marks

> Ethanoic acid is the second member of the homologous series of carboxylic acids. Its functional group is –COOH. Carboxylic acids have typical acidic properties, including reactions with carbonates.

## Mark scheme (5 marks)

1. Bubbles / effervescence are observed
2. The calcium carbonate (solid) disappears / dissolves
3. Carboxylic acids react with carbonates because they have typical acidic properties
4. Carbon dioxide gas is produced (causing the bubbles)
5. A calcium salt (calcium ethanoate) and water are also produced

## Key terms

- [carbonate](https://www.gradenine.co.uk/glossary/carbonate)

## Related

- [Revision notes for OCR A-Level Chemistry B: Salters (H433)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/ethanoic-acid-is-a-carboxylic-acid-94df1566) · Published by Druglandscape Ltd.