A biochemist analyzed a spinach leaf extract containing carotene and lutein pigments using two different chromatography stationary phases: Matrix A and Matrix B.
The table below shows the results of the analysis:
| Stationary Phase | Pigment | Distance moved by pigment (cm\text{cm}cm) | Distance moved by solvent (cm\text{cm}cm) | RfR_fRf value |
|---|---|---|---|---|
| Matrix A | Carotene | 12.0 | 16.0 | 0.75 |
| Matrix A | Lutein | 4.0 | 16.0 | 0.25 |
| Matrix B | Carotene | ddd | 16.0 | 0.70 |
| Matrix B | Lutein | 5.6 | 16.0 | 0.35 |
Calculate the distance moved by the carotene pigment on Matrix B, represented by ddd.
Explain which stationary phase (Matrix A or Matrix B) has a stronger attraction to lutein, using the RfR_fRf values from the table.
28 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.