(a) Crystallization
Crystallization is used for purification of solid organic compound. In this technique, substances are dissolved in the hot solvent up to the saturation level. The substance gets crystallize after cooling down the solvent. Insoluble impurities can be separated by filtration while solvent is still hot. The pure crystals of solid organic compound are collected by filtration, washed with the help of cold solvent for removing the impurities upon the surface.
