# Putrescine is a diamine produced when proteins decompose. It has a strong, unpleasant odour. Putrescine contains two amine groups and dissolves readily in water to produce an alkaline solution. Compare the properties of putrescine with those of ammonia, and explain why both compounds produce alkaline solutions when dissolved in water.

> Eduqas A-Level Chemistry — 4.6 Amines · Compare · 5 marks

> Putrescine is a diamine produced when proteins decompose. It has a strong, unpleasant odour. It contains two amine groups and dissolves readily in water to produce an alkaline solution.

## Mark scheme (5 marks)

1. Both putrescine and ammonia contain nitrogen (with a lone pair of electrons) / both are nitrogen-containing compounds
2. Both accept a proton (H⁺) from water / both react with water to produce hydroxide ions (OH⁻)
3. This produces an alkaline solution because OH⁻ ions are present in excess
4. Putrescine is an amine / organic compound, whereas ammonia is an inorganic compound
5. Putrescine has two amine (–NH₂) groups, whereas ammonia has one nitrogen / no carbon chain attached

## Key terms

- [amine](https://www.gradenine.co.uk/glossary/amine)
- [diamine](https://www.gradenine.co.uk/glossary/diamine)
- [alkaline](https://www.gradenine.co.uk/glossary/alkaline)
- [ammonia](https://www.gradenine.co.uk/glossary/ammonia)

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- [How to answer "Compare" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/putrescine-is-a-diamine-produced-when-3535aff4) · Published by Druglandscape Ltd.