# A student carries out paper chromatography on two ink samples, Ink A and Ink B, using two different solvents. In solvent 1, both inks produce a single spot at the same position. In solvent 2, Ink A still produces a single spot, but Ink B produces three separate spots. Explain what these results tell the student about the composition of each ink.

> AQA GCSE Chemistry (8462) — 4.8.1 Purity, formulations and chromatography · Explain · 4 marks

## Mark scheme (4 marks)

1. Ink A is a pure substance / contains only one compound
2. A pure compound produces a single spot in all solvents
3. Ink B is a mixture / contains more than one compound
4. The three spots in solvent 2 show that the components of Ink B have different Rf values / travel different distances because they have different solubilities in that solvent

## Key terms

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

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](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-carries-out-paper-chromatography-83cf7312) · Published by Druglandscape Ltd.