What is the difference between distillation, distillation under reduced pressure and steam distillation ?

Explanation

Disstillation involves the conversion of a liquid into vepour by heating followed by the condensation of the vapour thus produced by cooling. This method is commonly used for those liquids which are sufficiently stable at their boiling points and which contain non-volatile impurities for example simple organic liquids such as benzene, ethanol ecetone, chloroform carbon, tetrachloride, toluence, etc. , can be purified by simple distillation. Distillation under reduced pressure. On the other hand, is applicable for the purificatgion of liquids with high boiling points and liquids which decompose at or below their boiling. A liquid boils when its vapour pressure becomes equal to the external pressure. Clearly. the same liquid will boil at a lower temperature if the pressure on it is reduced. Since the liquid now boils at a lower temperature, the decomposition of the liquid does not occur. Steam distillation is used for the separation and purification of organic compounds (solid or liquid) from non-volatile organic or inorganic impurities. This method is applicable to only those sompounds which are volatile is steam, insolubl in water, possess high vapour pressure, and contain non-volatile impurities.