1. describe the processes involved in the extraction and separation of photosynthetic pigments from a leaf extraction  grind leaves in fine sand - to rupture cells and release pigments  grind leaves in acetone - extracts large quantity of soluble pigments  filter / centrifuge mixture - removes cell debris

2. separation  chromatography - pigments with different solubility carried different distances along paper by petroleum ether solvent  repeated spotting of extract - to allow pigment bands to be seen after separation  drying between spotting - to prevent spreading of spot  paper not touching sides - to ensure solvent rises uniformly  spot above solvent level - to prevent extract dissolving in solvent  paper left in solvent for suitable time - to allow separation of pigments to occur  solvent front marked at finish - solvent evaporates rapidly

3. calculate a pigment’s Rf value from a chromatogram divide the distance moved from the line of origin by the pigment front by the distance moved by the solvent front