Question

Distillation is a process of separating the component substances from a liquid mixture by:
A.Selective evaporation
B.Condensation
C.Both A and B
D.None of the above

Answer 1

Hint: Many a times, we find compounds are found together in the form of mixtures. It is necessary to separate them in order to use them individually. A mixture may contain 2 or more constituents that can be useful in different scenarios. Hence, to separate these compounds from the mixture, we employ different separation techniques. The separation techniques used depend on the physical as well as chemical properties of the compounds present in the mixture.

Complete Step-by-Step Answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
In a mixture containing solid particles of variable sizes, we would use an instrument known as a sieve to separate the smaller particles from the bigger ones. Similarly, if we were to separate a solute like salt from water, we would simply evaporate the solution to obtain the solute.
But in the case of a mixture of liquids, it becomes difficult to literally pick and separate the constituting liquids. In such a case, we could employ a method known as distillation. Distillation uses a simple principle known as selective evaporation. Let us discuss this in detail. If a mixture has liquids which have a significant difference in their boiling points, then we have the temperature of the system to boil and evaporate these liquids one at a time. This would result in the formation of the vapours of one of the liquids at its boiling temperature, while the other liquids are still in their liquid state. Now, to obtain liquid from these vapours, they are collected separately and allowed to cool. This process is known as condensation. In this way, by increasing the temperature of the system further, we can separate each liquid from the mixture one by one.

Hence, Option C is the correct option

Note: Now, depending on the nature of liquids involved, different types of apparatus and techniques have been developed to carry out distillation. Even though the methods to carry forward the process are different, the main principle remains the same.