Which of the following has the lowest boiling point ?

Options

A. (a)
B. (b)
C. (c)
D. (d)

Answer

D

Explanation

For C atoms alkane, van der Waals forces of attraction are weak and boiling point is the lowest. As far as the boiling points are concerend, alkenes have more boiling point than alkanes with the same number of C atoms. Due to of the presence of `pi`-bonds, more is the slightly polar. More is the number of `pi`-bonds, more is the polarity and higher is the boiling point. Thus, the decreasing order of boiling points is: c gt b gt a gt d.