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Exam Tips for Chromatography

Part of Chromatography · GCSE GCSE Chemistry revision

This exam tips covers Exam Tips for Chromatography within Chromatography for GCSE Chemistry. Revise Chromatography in Chemical Analysis for GCSE Chemistry with 23 exam-style questions and 15 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 12 of 13 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.

Topic position

Section 12 of 13

Practice

23 questions

Recall

15 flashcards

💡 Exam Tips for Chromatography

🎯 Common Question Types:

  • Calculate Rf values from distance data (1–2 marks)
  • Describe the paper chromatography method (3–4 marks)
  • Interpret a chromatogram: identify pure/mixture, match substances (2–3 marks)
  • Explain why substances separate (2 marks)
  • Evaluate the method — limitations and improvements (2–3 marks)

📝 Key Command Words:

  • Describe: State observations — number of spots, positions
  • Explain: Give reasons why separation occurs (different affinities for phases)
  • Calculate: Use Rf = substance distance ÷ solvent distance, show all working
  • Suggest: Use knowledge to propose improvements or reasons

⚠️ Common Mistakes to Avoid:

  • Confusing mobile and stationary phases (mobile MOVES)
  • Measuring from wrong starting point — always from the START LINE
  • Giving Rf values greater than 1 — impossible, recheck measurements
  • Adding units to Rf values — there are none (it is a ratio)
  • Assuming one spot always means pure — it could be two substances with same Rf

Keep building this topic

Read this section alongside the surrounding pages in Chromatography. That gives you the full topic sequence instead of a single isolated revision point.

Exam FocusKnowledge Organiser: ChromatographyThe Science Behind Solving CrimesWhat is Chromatography?

Practice Questions for Chromatography

What is the purpose of chromatography?

  • A. To separate the components of a mixture
  • B. To measure the mass of a substance
  • C. To change a substance from a solid to a liquid
  • D. To make a substance more concentrated
1 markfoundation

Explain how a chromatogram can be used to determine whether a substance is pure or a mixture.

3 marksstandard

Quick Recall Flashcards

What does Rf stand for and what does it measure?
Rf = Retention factor. It measures how far a substance travels compared to the solvent (distance moved by substance ÷ distance moved by solvent)
What is chromatography?
A separation technique used to separate mixtures into their individual components based on different affinities for mobile and stationary phases

23 questions on Chromatography — practise free

Instant marking, adaptive difficulty, and 15 spaced repetition flashcards. Free until your GCSEs.

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Knowledge Organiser: Chromatography