# A student places a piece of magnesium ribbon into a beaker of dilute hydrochloric acid. The beaker feels warm to the touch. Explain what type of reaction is occurring and why the beaker feels warm.

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

> Magnesium reacts vigorously with dilute hydrochloric acid, producing magnesium chloride and hydrogen gas. The student notices the beaker becomes noticeably warm during the reaction.

## Mark scheme (4 marks)

1. The reaction is exothermic
2. Energy is transferred to the surroundings
3. The energy released when bonds form in the products is greater than the energy needed to break bonds in the reactants
4. This causes the temperature of the surroundings (the beaker/solution) to increase

## 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-places-a-piece-of-b1c30eca) · Published by Druglandscape Ltd.