Question

In fractional distillation, the cooled and compressed air is passed through:
A. condenser
B. centrifuge
C. separator
D. autoclave

Answer 1

Fractional distillation is a process of the separation of a liquid mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. It uses distillation to fractionate. Generally the component parts have the boiling points that differ by less $25^{\circ}$ than from each other under the pressure of one atmosphere. If the difference in boiling points is greater than $25^{\circ}$,a simple distillation is typically used.

Complete answer:
Fractional distillation in a laboratory makes use of common laboratory glassware and apparatuses, typically including a Bunsen burner, a round-bottomed flask and a condenser, as well as the single-purpose fractionating column. The fractionating column is composed of various smaller parts which have their own function. They are:
(i) source of heat, such as a hot plate with a bath
(ii) a distilling flask, typically a round-bottom flask
(iii) a receiving flask, often also a round-bottom flask
(iv) a fractionating column, made up of several compartments
(v) a distillation head
(vi) Thermometer
(vii) a condenser
(viii) a separator
When the liquid mixture is distilled using fractional distillation, the cooled and compressed air is passed through the separator where the individual components get separated through various different compartments according to their boiling points. The gas is cooled and compressed in the condenser and then moved to the separator.

So, the correct answer is Option C.

Note:
The fractional distillation finds greater application in the petroleum industry. The fractional distillation is used in oil refineries to separate crude oil into useful substances (or fractions) having different hydrocarbons of different boiling points. The hydrocarbon of least boiling point is separated first and the hydrocarbon with the highest boiling point separates at last.