Question

Write the significance of dipole moment.

Answer 1

Significance of dipole moment:

(i) Distinction between polar and non polar molecules:

Non polar molecules such has nitrogen, oxygen and hydrogen have zero dipole moment whereas polar molecules have non zero dipole moment. For example, the dipole moment of water, HF, HCl and H₂​S are 1.85D, 1.78D, 1.07D and 0.95 D respectively.

(ii) Degree of polarity in a molecule: Greater is the value of dipole moment, greater is the degree of polarity. This relationship specially holds true for diatomic molecules.  HF (1.78D) is more polar than HCl (1.07D).

(iii) Shapes of molecules:

Water and carbon dioxide have dipole moments 1.85 D and 0 respectively.
Thus, water has angular shape whereas carbon dioxide has linear shape.