# Explain why zinc is often used to protect iron structures, such as oil pipelines, from corrosion.

> Edexcel GCSE Chemistry (1CH0) — 5.1 Transition metals, alloys and corrosion (Chem only) · Explain · 4 marks

> Iron structures buried underground or submerged in water are prone to corrosion. One method used to protect these structures involves attaching blocks of zinc directly to the iron.

## Mark scheme (4 marks)

1. The process described is sacrificial protection
2. Zinc is more reactive than iron
3. Zinc corrodes/reacts preferentially instead of the iron
4. The iron/steel is therefore protected from corrosion (for as long as the zinc remains)

## Key terms

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

## Related

- [Revision notes for Edexcel GCSE Chemistry (1CH0)](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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