Question

In this set X and Y cannot be

A. Acetone + water
B. Hexane + toluene
C. Ether + toluene
D. Mixture of gases from air

Answer 1

The set- up given in the picture is of Fractional distillation which is used to separate two or more miscible liquids having different boiling points by distillation. Here, distillation is a process to purify a liquid in which the components or substances in a liquid mixture are separated by using boiling or condensation.

Complete step by step answer:
- Here we are given a separation process set – up for distillation, in which we heat a liquid to form vapours and then cool the vapours back to get the liquid back.
- The final product we get after condensing the vapour is known as distillate.
- We know that miscible liquids are those which are soluble in each other and do not form a separate layer, while liquids which form a separate layer are known as immiscible liquids.
- A mixture of immiscible liquids is separated using a separating funnel.
- Now in question we need to focus on separating process of miscible liquid i.e. Fractional distillation.
- In this process of separating two or more miscible liquids by distillation we collect the distillate in fractions boiling at different temperatures.
- The separation of liquids depends on their difference in boiling points.
- The fractionating column is a long vertical glass tube filled with glass beads, these beads provide a large surface area for the hot vapours to cool and then condense repeatedly.
- In the column the highest temperature is at the bottom of the column and lowest is near its top.
- The fractionating column is fitted in the neck of the distillation flask which contains the mixture of liquids to be separated.
- In this method the more volatile liquid – having low boiling point, distils first and less volatile liquid – having higher boiling point distills later.
- It is used in laboratories to separate mixtures of miscible liquid, to separate crude oil petroleum into useful fractions such as kerosene, petrol, and diesel.
Since in the given picture we can see that distillate so X and Y cannot be option D. Mixture of gases because the end product we get if we use gases will be in gaseous form.

Note:
Acetone + water , Hexane + toluene , Ether + toluene are all examples of miscible liquids and we can use fractional distillation to separate them ,mixture of gases can also be separated through fractional distillation but as given in the picture the final product is distillate which cannot be obtained in the case of gases.