Question

Dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.

Give reason :

Answer 1

The dipole moment of chlorobenzene is less than cyclohexyl chloride as in chlorobenzene because $C-Cl$ bond is $s{p}^2$ hybridised whereas in cyclohexyl chloride the $C-Cl$ bond is $s{p}^3$ hybridised.

Since $s{p}^2$ more $s$ character and more electronegative than $s{p}^3$ so dipole moment of chlorobenzene is lower.

Also, in chlorobenzene resonance gives rise to the partial double bond character to the carbon-halogen bond, making it stronger by reducing the polarity of the carbon-halogen bond.

Hence dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.