Question

Due to back bonding observed dipole moment of whole molecules is found to be different than expected dipole moment

Answer 1

Firstly, we should know about what really is backbonding! (Base/concept should be clear about it.

Backbonding is the sharing of electrons between an atomic orbital on one atom with an antibonding π* orbital on another atom.You see backbonding in the formation of metal-carbonyl compounds such as Ni(CO)₄.