Experimental techniques, chromatography and separation

Learning objectives

Name appropriate apparatus for measuring time, temperature, mass and volume (stopwatches, thermometers, balances, burettes, volumetric pipettes, measuring cylinders and gas syringes), and suggest advantages and disadvantages of experimental methods and apparatus

Define a solvent, a solute, a solution and a saturated solution

Describe an acid–base titration using a burette, a volumetric pipette and a suitable indicator, and identify the end-point from the colour change of the indicator

Describe how paper chromatography separates mixtures of soluble coloured substances using a suitable solvent, and interpret chromatograms to identify unknown substances by comparison with known ones and to distinguish pure from impure substances

Describe the use of a locating agent to reveal colourless substances on a chromatogram, and state and use the equation Rf = distance travelled by the substance ÷ distance travelled by the solvent (Extended)

Describe and explain methods of separation and purification (dissolving in a suitable solvent, filtration, crystallisation, simple distillation and fractional distillation), suggest suitable techniques for a given mixture, and identify substances and assess their purity from melting and boiling point data