Which of the following is incorrect regarding the alkanes?

Options

A. (1) All the bonds in the molecules of alkanes are sigma bonds.
B. (2) The hybridization of every `C` atoms in alkanes is `sp^(3)`.
C. (3) The bond angles at the `C` atoms of all alkanes are tetrahedral, i.e., `109.5^(@)`.
D. (4) The rotation of group joined by a single bond usually requires a large amount of energy.

Answer

D

Explanation

A sigma bond (i.e., any non-multiple bond) has cylindrical symmetry along the bond with respect to the bonded atoms. Therefore, rotation is practically unhindered.