# Ethene is produced by cracking long-chain hydrocarbons. Ethene can be used as a monomer to make poly(ethene). Describe the process of addition polymerisation and explain why ethene, rather than ethane, is able to undergo this reaction.

> AQA A-Level Chemistry (7405) — 3.3.8 Aldehydes and ketones (A-Level only) · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Addition polymerisation involves many small molecules (monomers) joining together
2. To form a very large molecule / polymer
3. No other product / no small molecule is lost in addition polymerisation
4. Ethene has a carbon-carbon double bond (making it unsaturated)
5. The double bond opens / breaks to allow monomers to link together, whereas ethane has no double bond so cannot polymerise

## Key terms

- [addition polymerisation](https://www.gradenine.co.uk/glossary/addition-polymerisation)
- [monomer](https://www.gradenine.co.uk/glossary/monomer)
- [polymer](https://www.gradenine.co.uk/glossary/polymer)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/ethene-is-produced-by-cracking-long-chain-1367687f) · Published by Druglandscape Ltd.