# Ethanoic acid is a carboxylic acid. Explain why ethanoic acid is described as a weak acid and describe what is observed when ethanoic acid reacts with sodium carbonate.

> Edexcel A-Level Chemistry (9CH0) — 17.3 Carboxylic acids and derivatives · Explain · 5 marks

> Ethanoic acid (CH₃COOH) is the carboxylic acid found in vinegar. It can react with several substances, including sodium carbonate (Na₂CO₃).

## Mark scheme (5 marks)

1. Ethanoic acid is partially/incompletely dissociated (ionised) in aqueous solution
2. This means only a low concentration of H⁺ ions (or H₃O⁺) is produced compared to a strong acid
3. Effervescence / bubbling is observed when ethanoic acid reacts with sodium carbonate
4. Carbon dioxide gas is produced in the reaction
5. A salt (sodium ethanoate) and water are also formed as products

## Key terms

- [weak acid](https://www.gradenine.co.uk/glossary/weak-acid)
- [carboxylic acid](https://www.gradenine.co.uk/glossary/carboxylic-acid)
- [sodium carbonate](https://www.gradenine.co.uk/glossary/sodium-carbonate)

## Related

- [Revision notes for Edexcel A-Level Chemistry (9CH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" 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-3b3bac80) · Published by Druglandscape Ltd.