# A student is trying to separate two miscible liquids collected from a chemical reaction — ethanol and water. Explain how fractional distillation could be used to separate these two liquids.

> OCR GCSE Chemistry A: Gateway Science (J248) — C2.1 Purity and separating mixtures · Explain · 4 marks

> Ethanol boils at 78 °C and water boils at 100 °C. When mixed together, ethanol and water form a mixture that cannot be separated by simple distillation alone.

## Mark scheme (4 marks)

1. The mixture is heated in a fractionating column
2. Ethanol has a lower boiling point so it evaporates / vaporises first
3. The two liquids are collected as separate fractions because they have different boiling points
4. The vapour is cooled / condensed to collect each liquid

## Key terms

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

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](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-is-trying-to-separate-b4a9f88c) · Published by Druglandscape Ltd.