# Magnesium ribbon is added to copper sulfate solution. The magnesium displaces copper from the solution. Explain what happens during this reaction in terms of oxidation and reduction, identifying which substance is oxidised and which is reduced, and explaining why this reaction is classed as a redox reaction.

> WJEC A-Level Chemistry (Wales) — 1.8 Redox · Explain · 5 marks

> When magnesium ribbon is placed into blue copper sulfate solution, the blue colour fades and a reddish-brown solid forms on the magnesium. The overall equation for the reaction is: Mg + CuSO₄ → MgSO₄ + Cu

## Mark scheme (5 marks)

1. Magnesium is oxidised
2. Magnesium loses electrons (or magnesium gains oxygen / loses hydrogen — but electron loss is the key definition here)
3. Copper ions are reduced
4. Copper ions gain electrons (or copper loses oxygen)
5. The reaction is classed as redox because oxidation and reduction occur simultaneously (in the same reaction)

## Key terms

- [oxidation](https://www.gradenine.co.uk/glossary/oxidation)
- [reduction](https://www.gradenine.co.uk/glossary/reduction)
- [redox](https://www.gradenine.co.uk/glossary/redox)

## Related

- [Revision notes for WJEC A-Level Chemistry (Wales)](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/magnesium-ribbon-is-added-to-copper-aa6520e5) · Published by Druglandscape Ltd.