# Copper(II) oxide is a black solid. When copper(II) oxide is heated with carbon, a displacement reaction occurs, producing copper metal and carbon dioxide. Explain what has happened to the copper and the carbon in this reaction in terms of oxidation and reduction, and identify which substance is the oxidising agent.

> OCR A-Level Chemistry B: Salters (H433) — 2.3 Acid-base and redox reactions · Explain · 5 marks

> Copper(II) oxide is a black solid that reacts with carbon when heated. The products of the reaction are copper metal and carbon dioxide gas.

## Mark scheme (5 marks)

1. Copper(II) oxide / copper ions have been reduced
2. Copper (ions) have gained electrons OR oxygen has been removed from copper(II) oxide
3. Carbon has been oxidised
4. Carbon has gained oxygen OR carbon has lost electrons
5. Copper(II) oxide is the oxidising agent

## Key terms

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

## Related

- [Revision notes for OCR A-Level Chemistry B: Salters (H433)](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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