Chromatography and Separation Techniques IGCSE Chemistry: Complete Guide

🧪 Understanding Separation in IGCSE Chemistry

Separation techniques isolate pure substances from mixtures. This guide covers chromatography, distillation, and other methods.

🧠 Memory Tips

Separation Methods: “Filter Distill Chromatography Crystallize”

• Filtration: Separate solids from liquids
• Distillation: Separate by boiling points
• Chromatography: Separate by movement rates
• Crystallization: Obtain pure solids

Chromatography: “Mobile Stationary Rf”

• Mobile phase: Moves substances
• Stationary phase: Fixed support
• Rf: Retention factor calculation

📚 Key Concepts

Types of Separation

• Physical separation: No chemical change
• Based on properties: Size, solubility, boiling point
• Mixtures only: Cannot separate compounds
• Reversible: Original substances unchanged

Filtration

• Purpose: Separate insoluble solids from liquids
• Method: Pour through filter paper
• Examples: Sand from water, precipitates
• Equipment: Funnel, filter paper, beaker

Distillation

• Simple distillation: Separate liquid from solid
• Fractional distillation: Separate liquids
• Principle: Different boiling points
• Applications: Purify water, separate crude oil

Chromatography

• Paper chromatography: Separate dyes, amino acids
• Principle: Different movement rates
• Mobile phase: Solvent moves up paper
• Stationary phase: Paper or silica gel

🎯 Exam Focus

Common Questions:

1. Describe separation methods (5 marks)
2. Calculate Rf values (3 marks)
3. Explain chromatography principles (4 marks)
4. Choose appropriate separation technique (4 marks)

Key Calculations:

• Rf = Distance moved by substance / Distance moved by solvent
• Always between 0 and 1

🚀 Master Separation Techniques

Excel in separation chemistry with comprehensive practical methods and analysis.

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