# Copper(II) sulfate solution is electrolysed using inert electrodes. State what is observed at each electrode and identify the ion that is discharged at each electrode.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 1.9 Electrolysis · State · 4 marks

> Copper(II) sulfate solution contains copper(II) ions (Cu²⁺), sulfate ions (SO₄²⁻), hydrogen ions (H⁺), and hydroxide ions (OH⁻). Inert electrodes are used throughout the electrolysis.

## Mark scheme (4 marks)

1. At the cathode: a pink/orange-red solid is deposited (copper metal forms)
2. At the cathode: copper(II) ions / Cu²⁺ ions are discharged
3. At the anode: bubbles of gas are produced (oxygen gas is given off)
4. At the anode: hydroxide ions / OH⁻ ions are discharged

## Key terms

- [inert](https://www.gradenine.co.uk/glossary/inert)
- [ion](https://www.gradenine.co.uk/glossary/ion)
- [discharged](https://www.gradenine.co.uk/glossary/discharged)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "State" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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