# A fixed quantity of gas is trapped inside a rigid container at a constant volume. Explain why the pressure of the gas increases when its temperature is raised.

> WJEC GCSE Physics (Wales) — 2.3 Forces and motion · Explain · 4 marks

## Mark scheme (4 marks)

1. Increasing temperature increases the average kinetic energy (or speed/velocity) of the gas molecules
2. Faster-moving molecules collide with the walls of the container more frequently
3. Each collision exerts a greater force on the walls because the molecules are moving faster
4. Greater force per unit area on the container walls means greater pressure

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Physics (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" 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/a-fixed-quantity-of-gas-is-494d4126) · Published by Druglandscape Ltd.