Discuss the applications (or importance) of dipole moment.

(i) The degree of polarity in a molecule : In , the case of diatomic molecules, the greater the polarity of the molecule, greater is the dipole moment. For example, HF (μ = 1 . 91 D) is more polar than HCl (μ= I -03 D).
(ii)  The distinction between polar and non-polar molecules: Non-polar molecules like H₂, CO₂,CCl₄ etc. have zero dipole moment whereas polar molecules such as HCi, NH₃ and H₂O etc. have some value of dipole moment. The non-polar molecules may have polar or non-polar bonds.
(iii) Shapes of molecules. The value of dipole moment provides useful information about the shapes of molecules. For example, triatomic molecules having zero dipole moment have linear shape. For example, CO₂, CS₂ etc., while those triatomic molecules which have some dipole moment have angular shape. For example, H₂O (μ  =1.84) has an angular shape.