# Calcium oxide is produced when limestone is heated in a kiln. Describe how calcium oxide can be converted into calcium hydroxide, and explain one use of calcium hydroxide in agriculture.

> WJEC GCSE Chemistry (Wales) — 1.6 Limestone · Describe · 4 marks

## Mark scheme (4 marks)

1. Calcium oxide is reacted with water (to produce calcium hydroxide)
2. The reaction produces calcium hydroxide (slaked lime / limewater)
3. Calcium hydroxide is used to neutralise acidic soils
4. This improves crop growth (because most crops grow best in neutral or slightly alkaline conditions)

## Key terms

- [calcium oxide](https://www.gradenine.co.uk/glossary/calcium-oxide)
- [calcium hydroxide](https://www.gradenine.co.uk/glossary/calcium-hydroxide)

## Related

- [Revision notes for WJEC GCSE Chemistry (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/calcium-oxide-is-produced-when-limestone-42250de2) · Published by Druglandscape Ltd.