Lab techniques cover apparatus usage (burettes, pipettes, measuring cylinders), separation methods (filtration, distillation, chromatography), purity assessment (melting/boiling points), titrations, tests for ions/gases, and general practical skills like measuring temperature/time, with key techniques including titration for concentration, chromatography for mixtures, and distillation for separating liquids. Notes focus on practical application, apparatus drawing, and interpreting results like Rf values in chromatography. 

Key Lab Techniques & Concepts

1. Apparatus & Measurement

• Volumetric Pipette: For accurate, fixed volumes (e.g., 25 cm³).
• Burette: For accurate, variable volumes (e.g., titrations) – read from top (0.00) down.
• Measuring Cylinder: For approximate volumes.
• Thermometer: Measures temperature (use white tile for clarity).
• Time: Record in consistent units (e.g., seconds). 

2. Separation Techniques

• Filtration: Separates insoluble solids from liquids (using filter paper).
• Crystallisation: Purifies soluble solids by forming crystals from saturated solutions.
• Simple/Fractional Distillation: Separates liquids with different boiling points.
• Chromatography (Paper): Separates mixtures (dyes, inks) based on solubility/attraction to stationary/mobile phases; uses Rf values (Rf = distance solute / distance solvent). Use locating agents for colorless spots. 

3. Titrations (Acid-Base)

• Purpose: Determine unknown concentration.
• Apparatus: Pipette, burette, conical flask, white tile, indicator.
• Indicators: Phenolphthalein (colorless in acid, pink in alkali), Methyl Orange (red in acid, yellow in alkali).
• Method: Add indicator to fixed volume (pipette) in flask; titrate with unknown from burette to permanent (pale) color change; repeat for accuracy. 

4. Purity & Identification

• Purity: Assess by sharp melting/boiling points; impure substances have a range.
• Ion Tests: Flame tests for metal ions; precipitation tests for anions (e.g., halide ions with silver nitrate).
• Gas Tests: Test for H₂ (flame test), O₂ (glowing splint), CO₂ (limewater). 

5. General Practical Skills

• Drawing Apparatus: Know standard symbols (burette, condenser, etc.).
• Rates of Reaction: Investigating factors affecting speed.
• Electrolysis: Principles, molten salts, aqueous solutions. 

Resources for Notes

• Save My Exams: Offers detailed revision notes and past paper resources.
• YouTube: Channels like "Cambridge IGCSE Chemistry" provide video explanations