# Propene can be produced by cracking hydrocarbons from crude oil. Describe how propene can be used to make a polymer, and explain why propene is described as unsaturated.

> AQA A-Level Chemistry (7405) — 3.3.14 Organic synthesis (A-Level only) · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Propene is an alkene / contains a carbon–carbon double bond
2. Unsaturated means the molecule contains a carbon–carbon double bond / does not contain the maximum number of hydrogen atoms
3. Many propene monomers join together to form the polymer / addition polymerisation occurs
4. The double bond in propene opens / breaks to allow monomers to join together
5. The polymer formed is poly(propene) / a long-chain molecule with repeating units

## Key terms

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

## Related

- [Revision notes for AQA A-Level Chemistry (7405)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/propene-can-be-produced-by-cracking-8111ce66) · Published by Druglandscape Ltd.