Question

The dipolemoment of NH3
is much more than that of NF3
Explain

Answer 1

heya#mate

In both molecules i.e., NH3 and NF3, the central atom (N) has a lone pair electron and there are three bond pairs. Hence, both molecules have a pyramidal shape. Since fluorine is more electronegative than hydrogen, it is expected that the net dipole moment of NF3 is greater than NH3. However, the net dipole moment of NH3 (1.46 D) is greater than that of NF3 (0.24 D).

This can be explained on the basis of the directions of the dipole moments of each individual bond in NF3 and NH3. These directions can be shown as:

Since in case of NF3 , fluorine is more electronegative than nitrogen, so it will attract the shared pair of electron towards itself from nitrogen. As a result dipole due to all F is in opposite direction to the resultant dipole due to N-F bonds,therefore the net dipole decreases.

In NH3, Nitrogen is more electronegative than H, so it will attract the shared pair of electrons towards itself.As a result dipole due to Nitrogen is in same direction as the resultant dipole moment due to N-H bond& hence the net dipole increases.

Hence, the net dipole moment of NF

Answer 2

Answer:

In NH3 the orbital dipol due to lone pair and resultant dipol momentum os N-H bonds are in he same direction.

IN Nf3 orbitals dipole down to lone pair and  the  resut  dipole  moment of N-F bonds are in oppositr direction.