Question

Assertion : The boiling points of given compounds follow the order :
`CH_(3)CH_(2)CH_(2)CHO ~~CH_(3)CH_(2)CH_(2)CH_(2)CH_(3) lt CH_(3)CH_(2)CH_(2)CH_(2)OH ~~ H_(5)C_(2)OC_(2)H_(5)`
Reason : Boiling point depends upon molecualr mass only.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer 1

Correct Answer - D
The correct order is :
`CH_(3)CH_(2)CH_(2)CH_(2)CH_(3) lt H_(5)C_(2)OC_(2)H_(5) lt CH_(3)CH_(2)CH_(2)CHO lt CH_(3)CH_(2)CH_(2)CH_(2)OH`
Boiling point depends upon the nature of intermolecular forces, stronger the forces, higher is the boiling point.
`CH_(3)CH_(2)CH_(2)CH_(2)OH` molecules are associated due to extensive intermolecular hydrogen bonding,
`CH_(3)CH_(2)CH_(2)CHO` has stronger dipole-dipole attractions as compared to `H_(5)C_(2)OC_(2)H_(5) and CH_(3)CH_(2)CH_(2)CH_(2)CH_(3)` molecules have only van der Waals forces.