Question

(a) What is fractional distillation ? What is the use of fractionating column in fractional distillation ?
(b) Draw a labelled diagram of the fractional distillation apparatus used for separating a mixture of alcohol and water.

Answer 1

(a) Fractional distillation is a process of separating two or more miscible liquids by distillation. The distillate is collected in fractions, which boil at different temperatures. The principle behind this technique is the difference in boiling points of the liquids in the mixture.
The fractionating column is fitted in the neck of the distillation flask. Fractionating column provides different temperature zones inside the flask. The highest temperature is at the bottom and the lowest temperature is near its top.

(b)


Fig., Separation of mixture of alcohol and water by fractional distillation