# Ethanol can be produced by two different industrial and biological methods. Describe the differences between the fermentation of glucose and the hydration of ethene as methods of producing ethanol. Include the conditions required for each method.

> Cambridge International IGCSE Chemistry (0620) — 11.6 Alcohols · Describe · 4 marks

## Mark scheme (4 marks)

1. Fermentation uses glucose (sugar) as the raw material / hydration of ethene uses ethene (from crude oil/petroleum) as the raw material
2. Fermentation requires yeast / enzymes (from yeast) as a catalyst; hydration of ethene uses an acid catalyst (phosphoric acid / H₃PO₄)
3. Fermentation occurs at a low / warm temperature (approximately 30–40 °C); hydration of ethene occurs at a high temperature (approximately 300 °C)
4. Fermentation is a batch process producing dilute ethanol (must be distilled / purified); hydration of ethene is a continuous process producing pure / more concentrated ethanol

## Key terms

- [fermentation](https://www.gradenine.co.uk/glossary/fermentation)
- [hydration](https://www.gradenine.co.uk/glossary/hydration)
- [ethene](https://www.gradenine.co.uk/glossary/ethene)
- [glucose](https://www.gradenine.co.uk/glossary/glucose)

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Source: [GradeNine](https://www.gradenine.co.uk/q/ethanol-can-be-produced-by-two-6522bbae) · Published by Druglandscape Ltd.