Question
Which of the following molecules has the maximum dipole moment?
-
CO2
-
CH4
-
NH3
-
NF3
Solution
C.
NH3
CO2 and CH4 have zero dipole moment as these are symmetrical in nature. Between NH3 and NF3 , NF3 has greater dipole moment though in NH3 and NF3 both, N possesses one lone pair of electrons.
This is because, in the case of NH3, the net N-H bond dipole is in the same direction as the direction of the dipole of the lone pair but in the case of NF3, the direction of the net bond dipole of three -N-F bonds is opposite the that of the dipole of the lone pair.
