# Propanoic acid reacts with sodium carbonate solution. Describe what you would observe during this reaction and explain why carboxylic acids are described as weak acids.

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

> Propanoic acid (CH₃CH₂COOH) is a carboxylic acid found in some dairy products. Like all carboxylic acids, it can react with carbonates and only partially dissociates in water.

## Mark scheme (5 marks)

1. Observation: effervescence / bubbles / fizzing is seen
2. The gas produced is carbon dioxide (CO₂)
3. A weak acid only partially dissociates / ionises in water
4. A strong acid fully / completely dissociates in water
5. Carboxylic acids are weak because only a small proportion of their molecules release hydrogen ions (H⁺) in solution

## Key terms

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

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- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/propanoic-acid-reacts-with-sodium-carbonate-9a73ba54) · Published by Druglandscape Ltd.