Independent final check

Explain without the key

Explain

Final check

Explain: give reasons and connect them to evidence.

A pupil draws an ink baseline 10 mm above the paper bottom. Solvent is 15 mm deep. They plan to mark the front after drying. Explain all three faults. Describe a fresh setup and finishing sequence that avoids them.

Build your answer

Prepare the paper and solvent, with reasons

Develop and finish in order

Explain the key precautions

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Scope and sources

Cambridge IGCSE Chemistry 0620 · 2026–2028 v2 · Original learning materials.

0620 Extended12.3.1–4: suitable solvent, coloured and colourless paper chromatography, known/unknown comparison, purity evidence and Rf. Bounded12.4.2 method choice. Illustrative data; no real practical or chemical identity certification.

Apparatus, amounts and times in the experiment are illustrative. Real practical work follows a teacher-approved safety method.

Official Cambridge syllabus