Steam Distillation - Purification of Organic Compounds

This technique is applicable for the separation and purification of those organic compounds that are solids or liquids which (a) are insoluble in water (b) are volatile in steam (c) possess a high vapour pressure (10-15 mm Hg) at 373 K and (d) consist of non-volatile impurities.

Aniline (b. p. 457 K) can be purified by using steam distillation as it boils at a temperature of 371.5 K in presence of steam. Other compounds that can be purified by steam distillation are: nitrobenzene, o-nitrophenol, salicylaldehyde, o-hydroxyacetophenone, bromobenzene, necessary oils, turpentine oil and so on.