# Explain why the pressure of a fixed mass of gas increases when its temperature is increased, if the volume of the gas is kept constant.

> AQA A-Level Physics (7408) — 3.6.2 Thermal Physics · Explain · 5 marks

## Mark scheme (5 marks)

1. Gas particles are in constant random motion
2. Pressure is caused by particles colliding with the walls of the container
3. Increasing temperature increases the average kinetic energy of the particles / particles move faster
4. Faster particles collide with the walls more frequently
5. Each collision exerts a greater force on the walls / collisions are harder, so pressure increases

## Key terms

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

## Related

- [Revision notes for AQA A-Level Physics (7408)](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/explain-why-the-pressure-of-a-6787323e) · Published by Druglandscape Ltd.