A complete revision and exam practice pack for SC2c Paper Chromatography, covering the full Pearson Edexcel GCSE Chemistry (9–1) Separate Science specification for this topic (C2.7e, C2.9, C2.10, C2.11 core practical).

Topic Mastery Sheet (PDF) - a comprehensive student reference explaining how and why paper chromatography works from the underlying principle outward. The stationary phase (the paper and the water it absorbs) and mobile phase (the solvent) are introduced, and the mechanism of separation is explained clearly: each substance in a mixture distributes itself between the two phases according to its own solubility and affinity for the paper. Substances that prefer the mobile phase travel further; those that prefer the stationary phase barely move. The full core practical method is set out step by step with the reasoning behind each decision - why pencil is used for the baseline, why the paper must be above the solvent level, why the beaker is covered, and how to mark the solvent front. The Rf value section introduces the formula (distance moved by spot ÷ distance moved by solvent front) and works through a full example. Chromatogram interpretation is covered systematically: a single spot indicates a pure substance; multiple spots indicate a mixture; matching Rf values suggest the same substance; a spot that stays on the baseline was insoluble in the solvent. A worked example from the Edexcel exam paper (a student identifying two compounds from a reference table by calculating their Rf values) shows the full process in action. The stretch section covers HPLC, gas chromatography and the distinction between adsorption and absorption in the stationary phase.

Student Exam Practice Sheet (PDF + DOCX) - six exam-style questions including separation method MCQ, chromatography method description, why a dye stays on the baseline, an Rf value calculation to 2 decimal places, a three-mark ink comparison question, and an explanation of how chromatography separates a mixture.

Teacher Answer Key (PDF + DOCX) - full tick-point mark scheme with examiner notes.

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