Edexcel IGCSE Chemistry · Spec 1.11-1.13
Chromatography & Rf Values
How paper chromatography separates mixtures, and how to calculate Rf values.
Chemistry revision video
Chromatography & Rf Values
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Spec 1.11-1.13
What you need to know
- Describe how chromatography separates a mixture
- Calculate an Rf value
- Use chromatograms to identify substances
Active recall
Quick check
Answer each question before opening the answer.
How is an Rf value calculated?
Rf = distance moved by the spot ÷ distance moved by the solvent.
Why do different substances travel different distances in chromatography?
They have different solubilities and are attracted to the paper by different amounts.
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