# A student has a mixture of two liquids, ethanol and water. Explain how fractional distillation could be used to obtain a pure sample of ethanol from this mixture.

> WJEC GCSE Chemistry (Wales) — 1.3 Water · Explain · 4 marks

> Ethanol has a boiling point of 78 °C. Water has a boiling point of 100 °C.

## Mark scheme (4 marks)

1. The mixture is heated in a fractionating column
2. Ethanol has a lower boiling point than water, so it evaporates / boils first
3. The ethanol vapour rises up the fractionating column and is collected as a separate fraction
4. The ethanol vapour is cooled and condensed to give a pure liquid

## Key terms

- [fractional distillation](https://www.gradenine.co.uk/glossary/fractional-distillation)
- [fraction](https://www.gradenine.co.uk/glossary/fraction)

## Related

- [Revision notes for WJEC GCSE Chemistry (Wales)](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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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-has-a-mixture-of-a0fc81d0) · Published by Druglandscape Ltd.