# Ethene can be converted into ethanol by two different methods: hydration with steam, and fermentation. Compare these two methods in terms of the conditions required and the type of process involved.

> AQA GCSE Chemistry (8462) — 4.7.2 Reactions of alkenes and alcohols (Chem only) · Compare · 4 marks

## Mark scheme (4 marks)

1. Hydration requires a high temperature / high pressure (whereas fermentation does not / uses moderate/room temperature)
2. Hydration uses a catalyst (phosphoric acid) whereas fermentation uses yeast / an enzyme
3. Hydration is a continuous process whereas fermentation is a batch process
4. Fermentation produces a dilute solution of ethanol (which must be concentrated / distilled) whereas hydration produces ethanol directly / in a purer form

## Key terms

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

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