This exam tips covers Exam Tips for Chromatography within Chromatography for GCSE Chemistry. Revise Chromatography in Chemical Analysis for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. 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
20 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