# Methane (CH₄) is a hydrocarbon used as a fuel. When methane burns completely in excess oxygen, carbon dioxide and water are produced. Explain why burning methane is a chemical change and not a physical change.

> Eduqas GCSE Chemistry — 2.6 Carbon chemistry / organic chemistry · Explain · 4 marks

> Methane is the main component of natural gas and is widely used in domestic heating and cooking.

## Mark scheme (4 marks)

1. A chemical change requires a chemical reaction to occur
2. The products (carbon dioxide and water) have a different chemical composition to the reactant (methane)
3. A physical change only involves a change of state / only changes the form of the chemical
4. Burning methane is not a physical change because the chemical composition of the products is different from that of methane / the change cannot simply be reversed to recover methane

## Key terms

- [chemical change](https://www.gradenine.co.uk/glossary/chemical-change)
- [physical change](https://www.gradenine.co.uk/glossary/physical-change)

## Related

- [Revision notes for Eduqas GCSE Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/methane-ch-is-a-hydrocarbon-used-f1403ed9) · Published by Druglandscape Ltd.