# Chloroethene (CH₂=CHCl) is a monomer that undergoes addition polymerisation to form poly(chloroethene), also known as PVC. Describe the process of addition polymerisation and explain what happens to the double bond in chloroethene monomers during this process.

> AQA A-Level Chemistry (7405) — 3.3.12 Polymers (A-Level only) · Describe · 5 marks

> Poly(chloroethene), commonly known as PVC, is a widely used polymer made from the monomer chloroethene. Chloroethene contains a carbon-carbon double bond.

## Mark scheme (5 marks)

1. Many small molecules (monomers) join together to form a very large molecule (polymer)
2. The monomers are joined by covalent bonds
3. The carbon-carbon double bond in chloroethene breaks open / opens up
4. A single bond remains / is left between the two carbon atoms (after the double bond opens)
5. No other products / small molecules are formed (addition polymerisation produces only the polymer)

## 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)
- [double bond](https://www.gradenine.co.uk/glossary/double-bond)

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Source: [GradeNine](https://www.gradenine.co.uk/q/chloroethene-ch-chcl-is-a-monomer-that-b845819e) · Published by Druglandscape Ltd.