Question

A liquid is contaminated with non-volatile impurities. Suggest method of purification.
(A) Sedimentation
(B) Distillation
(C) Centrifugation
(D) Evaporation

Answer 1

Hint: Purification means removal of unwanted impurities present in an organic compound. The general methods of purification are sublimation, crystallization, distillation and many more. Moreover, the process of extracting something from a substance is also known as purification.

Complete step by step answer:
The method of purification of the organic compound depends mainly on the nature of the compound and the impurities present.
One easy method to check the purity of an organic compound is to either melt or boil it, as organic compounds tend to have sharp melting and boiling points.
Further, distillation is the process used for separating a liquid with non-volatile impurities. It is a separation technique used to either increase the concentration of a particular component in the mixture or to obtain pure components from the mixture. The process is as shown:

However, the distillation performed on a laboratory scale often uses batches of the liquid mixture whereas industrial distillation processes are generally continuous, requiring a constant composition of the mixture to be maintained.

Hence, option B is correct.

Note: Since a component in the mixture cannot have zero partial pressure, it is impossible to obtain a completely pure sample of a component from a mixture via distillation. Further, evaporation is a process of turning liquid to vapor. In case of sedimentation, the molecules or particles sediment downwards due to gravitational force and hence, centrifugation facilitates this process with centrifugal force by separating the particles into solid and liquid solvent.