# Describe the differences between catalytic cracking and steam cracking.

> AQA GCSE Chemistry (8462) — 4.7.1 Carbon compounds as fuels and feedstock · Describe · 4 marks

## Mark scheme (4 marks)

1. Catalytic cracking uses a hot powdered aluminium oxide catalyst
2. In steam cracking the hydrocarbon vapour is mixed with steam
3. Steam cracking requires a very high temperature (higher than catalytic cracking) / thermal decomposition occurs in steam cracking
4. Both methods first require the long-chain hydrocarbon to be heated to vaporise it / both produce smaller molecules including alkenes and alkanes

## Key terms

- [catalytic cracking](https://www.gradenine.co.uk/glossary/catalytic-cracking)
- [steam cracking](https://www.gradenine.co.uk/glossary/steam-cracking)
- [cracking](https://www.gradenine.co.uk/glossary/cracking)

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-the-differences-between-catalytic-cracking-0be28e0b) · Published by Druglandscape Ltd.