Question

Give reasons:

(i) C-Cl bond length in chlorobenzene is shorter than C-Cl bond length in CH₃-Cl.

(ii) The dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.

Answer 1

(i) In chlorobenzene each carbon atom is sp² hybridised. Due to resonance there is a partial double bond character , so bond length is short.

(ii) In chlorobenzene carbon to which chlorine is attached is sp² hybridised and and is more electronegative than the corresponding carbon in cyclohexyl chloride which is sp³ hybridised.