# Ethanol can be produced by two different industrial methods: fermentation of glucose and the hydration of ethene. Evaluate these two methods of producing ethanol, considering the raw materials used and the conditions required.

> Edexcel A-Level Chemistry (9CH0) — Topic 5 Organic chemistry II · Evaluate · 5 marks

> Ethanol is an important industrial chemical used as a fuel and solvent. It can be manufactured from renewable or non-renewable sources depending on the method chosen.

## Mark scheme (5 marks)

1. Fermentation uses glucose (from crops/sugar cane/starch) which is a renewable resource, whereas hydration of ethene uses ethene derived from crude oil which is a non-renewable resource.
2. Fermentation occurs at low temperatures (around 25–37 °C / room temperature) whereas hydration of ethene requires high temperatures and high pressures.
3. Fermentation uses yeast (enzymes) as a catalyst and is a batch process, which makes it slower and produces a lower rate of production compared to hydration.
4. Hydration of ethene produces a higher purity ethanol directly, whereas fermentation produces a dilute solution of ethanol that requires further processing (distillation) to purify it.
5. Overall judgement: fermentation is more sustainable/better for the environment due to use of renewable raw materials and lower energy conditions, but hydration is more economically efficient due to higher purity and faster continuous production.

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Chemistry (9CH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Evaluate" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/ethanol-can-be-produced-by-two-13158880) · Published by Druglandscape Ltd.