# Zinc nitrate solution is neutral. When zinc oxide powder is added to dilute nitric acid, a salt solution is formed. Explain why zinc oxide is described as a base, and describe how you could obtain pure, dry crystals of zinc nitrate from the resulting solution.

> Eduqas GCSE Chemistry — 2.2 Acids, bases and salts · Explain / Describe · 4 marks

> Zinc oxide is a white powder that does not dissolve in water. It reacts with dilute nitric acid to form zinc nitrate solution and water only.

## Mark scheme (4 marks)

1. A base is a substance that neutralises an acid (accepting / reacting with H⁺ ions / reacting with an acid to form a salt and water only)
2. Add excess zinc oxide to the acid to ensure all the acid is neutralised / reacted
3. Filter the mixture to remove excess unreacted zinc oxide
4. Evaporate / heat the filtrate (zinc nitrate solution) to remove water / concentrate the solution, then allow to cool so that zinc nitrate crystals form

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Explain / Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/zinc-nitrate-solution-is-neutral-when-8fd9b55f) · Published by Druglandscape Ltd.