Give reasons:

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

The reasons behind the dipole moment of chlorobenzene being lower than that of cyclohexyl chloride are:

i) The C-Cl bond in chlorobenzene is more electronegative due to sp³ hybridization whereas the C-Cl bond in cyclohexyl chloride is less electronegative due to sp² hybridization.

ii) In case of chlorobenzene, the C-Cl bond develops a partial double bond nature whereas the C-Cl bond in cyclohexyl chloride has single bond nature. Due to this, the C-Cl bond in chlorobenzene has shorter bond length.

And because the dipole moment is the product of charge and distance, and both the above-mentioned factors are lesser in case of chlorobenzene, it has lower dipole moment.