# Describe how paper chromatography can be used to find out whether a sample of ink contains a mixture of dyes or a single pure dye. Include in your answer how you would interpret the result.

> Cambridge International IGCSE Chemistry (0620) — 12.3 Chromatography · Describe · 4 marks

## Mark scheme (4 marks)

1. A spot of the ink is placed on the baseline of the chromatography paper (using a pencil line)
2. The paper is placed in a suitable solvent so the solvent level is below the baseline / spot
3. The solvent travels up the paper, carrying the dyes with it / dyes separate as they travel different distances
4. A single spot on the chromatogram shows a pure single dye; more than one spot shows the ink is a mixture

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-paper-chromatography-can-be-076b9043) · Published by Druglandscape Ltd.