# Explain why adding a catalyst increases the rate of a chemical reaction.

> OCR GCSE Chemistry A: Gateway Science (J248) — C5.2 Controlling reactions · Explain · 4 marks

> A chemical company produces ammonia on a large scale. Engineers use an iron catalyst in the process to ensure the reaction proceeds at a useful rate.

## Mark scheme (4 marks)

1. A catalyst provides a different reaction pathway
2. This new pathway has a lower activation energy
3. A greater proportion of particles now have at least the activation energy
4. The catalyst is not used up during the reaction

## Key terms

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

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-adding-a-catalyst-increases-cd51813a) · Published by Druglandscape Ltd.