# A student investigates the effect of temperature on the rate of a reaction between hydrochloric acid and sodium thiosulfate solution. As temperature increases, the rate of reaction increases. Explain why increasing temperature causes the rate of reaction to increase.

> Edexcel A-Level Chemistry (9CH0) — Topic 4 Physical chemistry and transition elements · Explain · 5 marks

> When sodium thiosulfate solution reacts with hydrochloric acid, a yellow precipitate of sulfur is produced. The student measures the time taken for a fixed amount of sulfur to form at different temperatures.

## Mark scheme (5 marks)

1. Increasing temperature increases the kinetic energy of the particles
2. Particles collide more frequently / more often
3. A greater proportion / more particles have energy greater than or equal to the activation energy
4. Therefore more collisions are successful / result in a reaction
5. So the rate of reaction increases (linked to the explanation above)

## Key terms

- [rate of reaction](https://www.gradenine.co.uk/glossary/rate-of-reaction)

## Related

- [Revision notes for Edexcel A-Level Chemistry (9CH0)](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-student-investigates-the-effect-of-13d5f55a) · Published by Druglandscape Ltd.