Branched chain alkanes have lesser boiling point than straight chain alkanes. Explain.

Explanation

Branched chain alkanes are more compact than the straight chain. The molecular size as well as the surface area of branched chain alkanes decreases. This decreases the vander waal.s forces of attraction. Thus, their boiling point also decreases. Hence, boiling point of branched chain alkanes is less than that of straight chain alkanes.
For example,
`underset("(b. pt=309 K)")underset("Pentane")(CH_3-CH_2-CH_2-CH_2-CH_3)" "underset("(b. pt = 301 K)")underset("2-Methylbutane")(CH_3-underset(CH_3)underset(|)(CH)-CH_2-CH_3)" "underset("(b. pt = 283 K)")underset("2,2-Dimethylpropane")(CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)C-CH_3)`