Which of the following is incorrect regarding the alkanes?

Options

A. (1) All the bonds in the molecules of alkanes are pi `pi)` bonds.
B. (2) The hybridization of two `C` atoms in alkanes is `sp^(2)`.
C. (3) There is a large energy barrier to rotation associated with groups joined by a double bond.
D. (4) The restricted rotation of groups joined by a double bond causes cis-trans isomerism.

Answer

A

Explanation

The molecules of alkenes contain just one pi `(pi)` bond (present in the carbon-carbon double bond). The rest of the bonds are sigma bonds. The strength of the `pi` bond is `264 kJ mol^(-1)` in comparison to the `sigma` bond `(13-26 kJ mol^(-1))`.