# A student adds copper carbonate powder to dilute sulfuric acid. The mixture fizzes and the copper carbonate gradually disappears. Explain what type of chemical change has taken place and give two pieces of evidence from the description that support this.

> WJEC GCSE Chemistry (Wales) — 2.2 Acids, bases and salts · Explain · 4 marks

> Copper carbonate is a green powder that is insoluble in water. When added to dilute sulfuric acid, the mixture fizzes and the green powder gradually disappears, leaving a blue solution.

## Mark scheme (4 marks)

1. Identifies the change as a chemical change
2. States that a chemical change produces products with a different chemical composition to the reactants
3. First piece of evidence: a gas is produced (fizzing / bubbling)
4. Second piece of evidence: a new substance with a different colour/appearance is formed (blue solution / green solid disappears)

## Key terms

- [chemical change](https://www.gradenine.co.uk/glossary/chemical-change)

## Related

- [Revision notes for WJEC GCSE 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/a-student-adds-copper-carbonate-powder-ca93887b) · Published by Druglandscape Ltd.