Question

Assertion: Benzene ( boiling point 353K ) and methanol ( boiling point $338K)$ are separated by simple distillation.
Reason: Fractional distillation is used to separate two liquids from their mixture when their boiling points differ by ${{25^\circ C}}$ or less.
(A) Both assertion and reason are correct and reason is the correct explanation for assertion.
(B) Both assertion and reason are correct but reason is not the correct explanation for assertion.
(C) Assertion is incorrect but reason is correct.
(D) Both assertion and reason are incorrect.

Answer 1

In the above question, some assertion about separation about benzene and methanol separation is given. We are provided with the information about fractional distillation. We have to check which of the following options suits the best.

Complete step by step solution
Simple distillation is a process in which two liquids having different boiling points can be separated. Simple distillation can be used to separate liquids that have at least twenty-five degrees difference in their boiling points. So, as the difference between boiling point of benzene and methanol is ( ${{353 - 338 = 15K}}$ ) is 15K. And hence, simple distillation cannot be used for separating benzene and methanol.
Fractional distillation is the separation of a mixture of liquid into its components. It uses distillation to fractionate and hence, the name is fractional distillation. Generally the component parts that have boiling points that differ by less than ${{25^\circ C}}$ from each other under a pressure of one atmosphere are separated by fractional distillation. And hence, the reason is true.
Since, reason is true and assertion is false.
Hence, option C is correct.

Note
-If the difference in boiling point of the mixture of liquid is less than ${{25^\circ C}}$ , then fractional distillation is used.
-If the difference in boiling point of the mixture of liquid is more than ${{25^\circ C}}$ , then fractional distillation is used.