2.2 (b) Methods of purification -Filtration: Mixture goes in a funnel with filter paper, into a flask. Residue is insoluble and stays at top. Filtrate goes through. Crystallisation: Some water in the solution is evaporated so the solution becomes more concentrated....
(a) Criteria of purity Paper chromatography: (To separate substances) a drop of the substance is placed at the centre of a piece of filter paper and allowed to dry. Three or four more drops are added to it. Water is dripped on, drip by drip, so the ink spreads...
2. Experimental techniques 2.1 Measurement Variable Time Temperature Mass Volume Apparatus Stopwatch Clock Thermometer (liquid in glass, thermistor or thermocouple) Balance -beaker (a) -burette (b) -pipettes (c) -measuring cylinder (d) -gas...