Question

Assertion (A) : It is not possible to separate the components of an azeotrope by fractional distillation.

Reason (R) : Minimum boiling azeotrope is formed by the solutions showing large positive deviation from Raoult's law.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Both statements are true. Separation fails because vapour and liquid have the same composition, not because of the deviation type.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
An azeotrope is a liquid mixture that boils at one fixed temperature and gives a vapour of the same composition as the liquid. Fractional distillation works only when the vapour and the liquid differ in composition.

Step 2: Check the Assertion (A).
At the azeotropic composition the vapour has the same composition as the liquid. Boiling does not change the mixture, so repeated distillation gives no separation. So (A) is TRUE.

Step 3: Check the Reason (R).
A solution with a large positive deviation from Raoult's law has weaker A-B attractions than A-A and B-B attractions. Its vapour pressure is higher than expected. So it boils at a lower temperature and forms a minimum boiling azeotrope. (R) is TRUE.

Step 4: Does R explain A?
The reason tells us how a minimum boiling azeotrope forms. It does not say why separation by distillation fails. The failure is due to equal vapour and liquid composition. Maximum boiling azeotropes, which come from negative deviation, also cannot be separated. So R is not the explanation of A.

Final Answer:
Both are true, but R does not explain A, so the code is (B). \[ \boxed{\text{Option (B)}} \]