Experimental techniques

C6.1 Physical and chemical changes 1 Identify physical and chemical changes, and understand the differences between them C12.1 Experimental design 1 Name appropriate apparatus for the measurement of time, temperature, mass and volume, including: (a) stop-watches (b) thermometers (c) balances (d) burettes (e) volumetric pipettes (f) measuring cylinders (g) gas syringes 2 Describe a: (a) solvent as a substance that dissolves a solute (b) solute as a substance that is dissolved in a solvent (c) solution as a mixture of one or more solutes dissolved in a solvent (d) saturated solution as a solution containing the maximum concentration of a solute dissolved in the solvent at a specified temperature (e) residue as a solid substance that remains after evaporation, distillation, filtration or any similar process (f) filtrate as a liquid or solution that has passed through a filter C12.4 Separation and purification 1 Describe and explain methods of separation and purification using: (a) a suitable solvent (b) filtration (c) crystallisation (d) simple distillation (e) fractional distillation 2 Suggest suitable separation and purification techniques, given information about the substances involved 3 Identify substances and assess their purity from melting point and boiling point information C12.3 Chromatography 1 Describe how paper chromatography is used to separate mixtures of soluble coloured substances, using a suitable solvent 2 Interpret simple chromatograms to identify: (a) unknown substances by comparison with known substances (b) pure and impure substances 3 State and use the equation for Rf: Rf = distance travelled by substance distance travelled by solvent