Question

Dipole moment of nf3 and nh3

Answer 1

Hello here is your answer...
Just looking at NH3 and NF3, you might assume that NF3 will have high dipole moment than NH3 as 'F' is more electronegative. But, NH3 has more dipole moment than NF3.

Let's see why that is so..

In NH3, N is more electronegative than H. So, N pulls the electrons from H towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen.



In NF3, F is more electronegative than N. So, all F atoms pull the electrons towards themselves. And, this resultant moment is opposite to the directions of that of the lone pair of electrons on the 'N' atom. And, since Dipole Moment is a vector quantity, the net dipole decreases.

And, so we have NH3 whose dipole moment .

I hope that this will help you...

Answer 2

In NH3, N is more electronegative than H. So, N pulls the electrons from H towards itself and so, the direction of moment due to the N-H bonds is in the same direction as that of the lone pair of electrons on Nitrogen. ... And, so we have NH3 whose dipole moment is much higher than that of NF3