# A sealed metal container holds a fixed quantity of gas. The container is placed in boiling water, causing the temperature of the gas to rise. Explain how and why the pressure of the gas changes as its temperature increases.

> Eduqas A-Level Physics — 2.3 Capacitance (A-Level only) · Explain · 5 marks

> A sealed metal container holds a fixed quantity of gas at room temperature. The container is then placed in boiling water.

## Mark scheme (5 marks)

1. The temperature of the gas increases, so the average kinetic energy of the gas molecules increases.
2. The molecules move faster / have greater velocities.
3. The molecules collide with the walls of the container more frequently.
4. The molecules collide with the walls with greater force.
5. Therefore the pressure of the gas increases, because pressure is the perpendicular force per unit area on the walls and the volume (area) stays constant.

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Physics](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-sealed-metal-container-holds-a-cc500354) · Published by Druglandscape Ltd.