Explain why A branched chain alkane possesses lower boiling point than the corresponding straight chain alkane.

Explanation

Branched chain makes the molecule more compact and decreases its surface area.
Due to reduction in surface area, branched chain molecule, has less contact with the adjacnet molecule.
This further decreases the extent of van der Waal.s forces existing between the two
Where as in a straight chain molecule has a large surface area and has more contact with the adjacent molecules.
Thus, the extent of van der Waal.s forces existing between the two molecules is greater.
As boiling point depends on magnitude of van der Waal.s forces, a branched chain alkane possesses lower boiling point than the corresponding straight chain alkane.