Which of the following hydrocarbons are most polar in nature?

Options

A. Alkanes
B. Alkenes
C. Alkynes
D. All are non-polar

Answer

C

Explanation

They are all basically ninpolar but alkynes are relatively more polar on account of more polarzation of their `pi`-electrons. Thus, alkynes are slightly more soluble in water than alkenes and alkanes.
For example but-1-yne has a larger dipole moment (0.80 D) than but-1-ene (0.30 D) because the C with more s character is more electronegative. Thus, a carbon-carbon bond involving sp hybrid C of but-1-yne is more polarized than a carbon-carbon bond involving `sp^2` hybrid C of but-1-ene.