# A sports injury pack is based on an endothermic reaction. When the pack is activated, its contents dissolve in water and the pack feels cold. Explain why the pack feels cold, using ideas about bonds and energy transfer to and from the surroundings.

> Eduqas GCSE Chemistry — C5 Energy changes · Explain · 4 marks

## Mark scheme (4 marks)

1. Energy must be supplied to break bonds in the reactants
2. The energy needed to break bonds is greater than the energy released when new bonds are formed
3. The reaction takes in / absorbs energy from the surroundings
4. The temperature of the surroundings decreases, which is why the pack feels cold

## Key terms

- [endothermic reaction](https://www.gradenine.co.uk/glossary/endothermic-reaction)
- [surroundings](https://www.gradenine.co.uk/glossary/surroundings)

## Related

- [Revision notes for Eduqas GCSE Chemistry](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-sports-injury-pack-is-based-c7730731) · Published by Druglandscape Ltd.