This comparison covers Interpreting Chromatogram Results 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 7 of 13 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.
⚖️ Interpreting Chromatogram Results
| Observation | Conclusion |
|---|---|
| One spot (moved up) | Sample is probably a single pure substance |
| Multiple spots | Sample is definitely a mixture of different substances |
| Spot stays at start line | Substance is insoluble in this solvent — try a different one |
| Spot at same position as known standard | Likely to be the same substance (same Rf value) |
| Streaky, elongated spots | Sample spot was too large; technique needs improvement |
Practice questions for Chromatography
What is the purpose of chromatography?
Explain how a chromatogram can be used to determine whether a substance is pure or a mixture.
Quick recall flashcards
What is chromatography?
A separation technique used to separate mixtures into their individual components based on different affinities for mobile and stationary phases
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)