# Ethanol (C₂H₅OH) can be produced by the fermentation of glucose (C₆H₁₂O₆). During fermentation, yeast converts glucose into ethanol and carbon dioxide. Explain why fermentation is described as a chemical change rather than a physical change.

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

> Ethanol is used as a fuel and as a solvent. It can be made from glucose by fermentation using yeast.

## Mark scheme (4 marks)

1. A chemical reaction takes place / a chemical change requires a chemical reaction
2. New substances / products are formed (ethanol and carbon dioxide)
3. The products have a different chemical composition to the reactant(s) / glucose
4. A physical change only changes the form / state of a substance, not its chemical composition — this does not happen here

## Key terms

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

## 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)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/ethanol-c-h-oh-can-be-produced-by-fdb14ed7) · Published by Druglandscape Ltd.