Free Chromatography questions for IGCSE Chemistry (0620), part of Experimental techniques & analysis. Each question has the answer and the marking points an examiner would look for.
Generate a full Chromatography worksheet →All Experimental techniques & analysis questionsTwo dyes, M and N, are separated by paper chromatography using water as the solvent. The solvent front moves 9.0 cm from the baseline. M moves 3.0 cm and N moves 7.0 cm.
What is the Rf value of M and which dye is more soluble in water?
| Rf value of M | more soluble dye | |
|---|---|---|
| A | 0.33 | M |
| B | 0.33 | N |
| C | 3.00 | N |
| D | 3.00 | M |
Answer: B
Fig. shows a chromatogram of dyes A, B, C and D and mixture X. Which dyes are in X?
Answer: C
Why is the baseline in chromatography drawn in pencil?
Answer: A
A chromatogram of a food colouring shows three spots. A known dye E102 is run alongside.
State how the chromatogram shows that the food colouring is a mixture.
Describe how the chromatogram shows whether E102 is present.
Explain how colourless amino acids can be seen on a chromatogram.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | more than one spot it gives more than one spot B1 | 1 |
| (b) | spot at same height / same Rf a spot in the food colouring is at the same height (same Rf) as E102 B1 | 1 |
| (c) | spray with locating agent spray with a locating agent (ninhydrin) B1 and dry/heat to show spots B1 | 2 |
Chromatography can be used to separate amino acids.
Explain why the chromatography paper is put in a covered tank.
Explain why different substances travel different distances.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | saturate air with solvent vapour to stop the solvent evaporating B1 | 1 |
| (b) | different solubility and attraction to paper they have different solubilities in the solvent B1 and different attraction to the paper B1 | 2 |
Paper chromatography is used to identify the dyes in an ink.
Explain why the start line is drawn in pencil and not ink.
Explain why the start line must be above the solvent level.
A dye travels 3.6 cm and the solvent front travels 9.0 cm. Calculate the Rf value.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | pencil insoluble, does not run pencil (graphite) does not dissolve in the solvent / will not run B1 | 1 |
| (b) | spots would dissolve into the solvent otherwise the dyes would dissolve into the solvent in the beaker B1 | 1 |
| (c) | 0.40 Rf = 3.6 ÷ 9.0 C1 0.40 A1 | 2 |
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in