# A student burns a piece of wood in a fireplace. The room feels warmer after the wood has been burning for a few minutes. Explain why the temperature of the room increases during this reaction, and describe what this tells us about the overall energy change of the reaction.

> OCR GCSE Chemistry A: Gateway Science (J248) — C3.1 Introducing chemical reactions · Explain · 4 marks

> When wood burns in a fireplace, a chemical reaction takes place between the wood and oxygen in the air. The room gradually becomes warmer.

## Mark scheme (4 marks)

1. Burning wood is an exothermic reaction
2. Energy is transferred to the surroundings (the room / air)
3. The energy released when bonds are formed in the products is greater than the energy needed to break bonds in the reactants
4. The overall energy change of the reaction is negative / the products have less energy than the reactants

## Key terms

- [overall energy change of the reaction](https://www.gradenine.co.uk/glossary/overall-energy-change-of-the-reaction)

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](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-burns-a-piece-of-515ef917) · Published by Druglandscape Ltd.