# Ethanol can be produced by fermentation. Describe the process of fermentation and explain why the ethanol produced this way is considered a renewable source of fuel.

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

## Mark scheme (5 marks)

1. Sugar (glucose) solution is broken down / converted
2. Yeast is used / yeast acts as a catalyst / biological catalyst
3. The process occurs anaerobically / in the absence of oxygen
4. Carbon dioxide is also produced / ethanol and carbon dioxide are the products
5. The sugar / glucose comes from plants which absorb carbon dioxide from the atmosphere, so the carbon dioxide released on combustion was recently removed from the atmosphere / the fuel is renewable because plants can be regrown

## Key terms

- [fermentation](https://www.gradenine.co.uk/glossary/fermentation)
- [ethanol](https://www.gradenine.co.uk/glossary/ethanol)
- [renewable](https://www.gradenine.co.uk/glossary/renewable)

## 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)
- [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-can-be-produced-by-fermentation-b7be4165) · Published by Druglandscape Ltd.