# Explain why electrolysis can occur in a solution of sodium chloride but not in solid sodium chloride.

> Cambridge International IGCSE Chemistry (0620) — 4.1 Electrolysis · Explain · 4 marks

## Mark scheme (4 marks)

1. In solution, the sodium chloride is dissociated / dissolved into ions (Na⁺ and Cl⁻)
2. These ions are free to move towards the electrodes
3. In solid sodium chloride, the ions are held in fixed positions in the lattice / cannot move
4. Electrolysis requires movement of ions to carry charge / complete the circuit; this is not possible in the solid

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-electrolysis-can-occur-in-8b01fb06) · Published by Druglandscape Ltd.