# Lead(II) bromide can be electrolysed when it is melted. During electrolysis, lead(II) ions gain electrons at the negative electrode to form lead metal, and bromide ions lose electrons at the positive electrode to form bromine gas. Explain which species is oxidised and which is reduced in this process, and state what is meant by the terms oxidation and reduction in terms of electron transfer.

> Eduqas A-Level Chemistry — 1.8 Redox · Explain · 5 marks

> During the electrolysis of molten lead(II) bromide, lead metal is deposited at the negative electrode and bromine gas is produced at the positive electrode.

## Mark scheme (5 marks)

1. Oxidation is the loss of electrons
2. Reduction is the gain of electrons
3. Bromide ions are oxidised (because they lose electrons to form bromine)
4. Lead(II) ions are reduced (because they gain electrons to form lead metal)
5. This reaction is described as a redox reaction because both oxidation and reduction occur simultaneously

## Key terms

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

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- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/lead-ii-bromide-can-be-electrolysed-when-314db3c1) · Published by Druglandscape Ltd.