Question -
Answer -
In heteronuclearmolecules, polarization arises due to a difference in the electronegativitiesof the constituents of atoms. As a result, one end of the molecule acquires apositive charge while the other end becomes negative. Hence, a molecule is saidto possess a dipole.
The product of the magnitude of the chargeand the distance between the centres of positive-negative charges is called thedipole moment (╬╝) of the molecule. It is a vector quantity and isrepresented by an arrow with its tail at the positive centre and head pointingtowards a negative centre.
Dipole moment (╬╝) = charge (Q) ├Чdistance of separation (r)
The SI unit of a dipolemoment is тАШesuтАЩ.
1 esu = 3.335 ├Ч 10тАУ30┬аCm
Dipole moment is the measure of the polarityof a bond. It is used to differentiate between polar and non-polar bonds sinceall non-polar molecules (e.g. H2, O2) have zero dipolemoments. It is also helpful in calculating the percentage ionic character of amolecule.
