# Ethene (C₂H₄) can be produced by two different industrial methods: the cracking of ethane (from crude oil) and the dehydration of ethanol (from fermentation of glucose). Evaluate which method of producing ethene is more sustainable, giving reasons for your answer.

> Edexcel A-Level Chemistry (9CH0) — Topic 3 Organic chemistry I · Evaluate · 5 marks

> Ethene is one of the most important industrial chemicals in the world, used to make poly(ethene) and many other products. Global demand for ethene continues to rise.

## Mark scheme (5 marks)

1. Cracking of ethane uses crude oil / a non-renewable / finite / fossil fuel resource
2. Fermentation uses glucose from plants / a renewable feedstock (so dehydration of ethanol is more sustainable in terms of raw materials)
3. Cracking requires high temperatures (and therefore uses large amounts of energy / is energy intensive), making it less sustainable
4. Fermentation / dehydration of ethanol produces ethene that is effectively carbon neutral / does not add net CO₂ to the atmosphere because plants absorbed CO₂ when growing
5. Reasoned conclusion stating that dehydration of ethanol / the plant-based route is more sustainable, with a linked reason (e.g. renewable feedstock / carbon neutral / long-term availability)

## Key terms

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

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/ethene-c-h-can-be-produced-by-64943f6f) · Published by Druglandscape Ltd.