Question

Fractional distillation method is used for the separation of different gases from air. why is it so?

Answer 1

Hint: The liquid air for separating different gases usually undergoes the process of fractional distillation. The usage of different boiling points of main elements of air is done for separating them. Fractional distillation is generally used for separating the two or more miscible liquids which tends to boil without decomposition.

Complete answer:
The air which is present in the atmosphere of Earth has gases such as nitrogen, argon, carbon dioxide, oxygen,and many others. So to separate the air sample into the primary components we need to cool the air more and thus this process of cooling the air further is known as the fractional distillation of the liquid air. Now the air separation unit is also required which is not unlike the conventional distillation tube which is used for purifying the water.
Now each of the gases has the significant boiling point which is the temperature at which the transformation of the liquid into the gas takes place. If we have the random air sample then the separation of them can be done by gradually cooling the sample till the each component of the gas liquefies. Then this liquefied component gets into the bottom of the collective vessel and then after when the liquid is being retrieved the cooling still continues till the temperature tends to drop to the boiling point of the next compound. The compounds such as that of carbon dioxide cannot liquefy. So we can separate the different gases in air by fractional distillation as they have different boiling points.

Note: The different ways for separating the mixture is separating funnel which is used for separating the components between the two immiscible liquid phases. The other method is chromatography which is used to separate the mixture components by passing it in suspension in which the mixture components move at different rates. Evaporation, simple distillation are another method for separating mixtures.