Question

Assertion: The boiling point of diethyl ether is greater than furan
Reason: Furan is more compact and has less surface area.
(A) Both assertion and reason are correct and reason is the correct explanation of assertion.
(B) Both assertion and reason are correct but reason is not the correct explanation of assertion.
(C) Assertion is correct but reason is incorrect
(D) Both assertion and reason are incorrect.

Answer 1

We know that the boiling point of a compound depends on the type of intermolecular forces existing between them. The boiling point of the compound is directly proportional to the surface area and the forces existing between them.

Complete step by step answer:
-As we know that the boiling point of a compound depends on the force of attraction existing between the compounds.
-So in diethyl ether, we have dipole-dipole interaction and dispersion forces such as Vanderwaal forces.
-In furan, there are weak attractive forces and there is compactness in its molecule and it has less surface so less boiling point as boiling point depends on the surface area.
-Also due to the more surface area of diethyl ether prevailing due to more atomic mass and greater -Vanderwaal attraction between the boiling point of diethyl ether has more boiling point than furan.
-So the assertion is right
-Also, the furan molecules have less surface area as due to compactness the atoms come closer leaving no distance between them, and consequently, the surface area decreases, and simultaneously boiling point decreases.
-So the reason is right

Therefore, the assertion and reason both are right and the reason is a correct explanation of assertion.

Note: In the given question one point to be noted is the effect of attractive forces on the boiling point and the increase/decrease in boiling point with an increase/decrease in surface area respectively. As the branching increases, the boiling point decreases because there is a decrease in surface area. In the case of n-butane and 2-methylpropane, n-butane has more boiling point.