# Explain why a real gas behaves more like an ideal gas at high temperature and low pressure.

> IB DP Chemistry Standard Level (2023 syllabus) — S1.5 Ideal gases · Explain · 4 marks

## Mark scheme (4 marks)

1. At low pressure, the average distance between molecules is large / molecules are far apart
2. Intermolecular forces / attractions between molecules become negligible / insignificant when molecules are far apart
3. At high temperature, molecules have high (average) kinetic energy
4. The kinetic energy is much greater than the potential energy of intermolecular attractions, so intermolecular forces have negligible effect on the motion of molecules

## Key terms

- [ideal gas](https://www.gradenine.co.uk/glossary/ideal-gas)
- [real gas](https://www.gradenine.co.uk/glossary/real-gas)

## Related

- [Revision notes for IB DP Chemistry Standard Level (2023 syllabus)](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-a-real-gas-behaves-84b5cd04) · Published by Druglandscape Ltd.