A conservator extracted a coloured substance, U, from a fabric. Substance U was compared with reference compounds A and B using paper chromatography.
In each test, U, A and B were run together on the same type of chromatography paper. The distances were measured from the origin line to the centre of each spot.
| Test | Distance moved by solvent in mm | Distance moved by U in mm | Distance moved by A in mm | Distance moved by B in mm |
|---|---|---|---|---|
| Solvent 1 | 80.0 | 32.0 | 32.0 | 32.0 |
| Solvent 2 | 75.0 | 45.0 | 45.0 | 30.0 |
The conservator concluded that U is compound A.
Evaluate the conservator's conclusion. Use calculations in your answer.
113 exam-style questions on AQA GCSE Chemistry 8.1 Purity, formulations and chromatography, covering 8.1.1 Pure substances, 8.1.2 Formulations, and 8.1.3 Chromatography. Each one has a worked solution and a mark scheme showing where the marks go.