Purity, formulations and chromatography

3 lessons in Chemical analysis.

15 exam questions · 21 marks

8.1 Pure substances and formulations What pure means in chemistry compared with everyday use, how melting and boiling points show whether a substance is pure, and what formulations are, with examples such as paints, medicines and fertilisers. AQA Edexcel OCR 5 questions 8.2 Paper chromatography and Rf values How paper chromatography separates mixtures using a stationary phase and a mobile phase, how to interpret a chromatogram to identify substances and tell pure from impure, and how to calculate Rf values. AQA Edexcel OCR 5 questions 8.3 Required practical: chromatography How to separate coloured substances such as food colourings or inks by paper chromatography, why the method uses a pencil baseline, a lid and a solvent level below the line, and how to calculate Rf values from the results. AQA Edexcel OCR 5 questions