# Explain how an increase in temperature increases the rate of a chemical reaction, with reference to both collision frequency and activation energy.

> IB DP Chemistry Higher Level (2023 syllabus) — R2.2 How fast? The rate of chemical change · Explain · 4 marks

## Mark scheme (4 marks)

1. An increase in temperature increases the average kinetic energy of particles, so particles move faster and collide more frequently.
2. A greater proportion / fraction of collisions have energy equal to or greater than the activation energy (Ea).
3. This is because the Maxwell–Boltzmann distribution shifts to higher energies at higher temperature, so the area under the curve beyond Ea is larger.
4. The combined effect of increased collision frequency and a greater proportion of successful collisions (those meeting both the energy and orientation requirements) results in a significantly increased rate of reaction.

## Key terms

- [activation energy](https://www.gradenine.co.uk/glossary/activation-energy)
- [collision frequency](https://www.gradenine.co.uk/glossary/collision-frequency)

## Related

- [Revision notes for IB DP Chemistry Higher 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-how-an-increase-in-temperature-ef653483) · Published by Druglandscape Ltd.