Which out of and
has a higher dipole moment and why?
Here both have a central atom Nitrogen and it has a lone pair of electrons with three bond pairs.
Hence both molecules have a pyramidal shape.
The electronegativity of fluorine is more as compared than that of hydrogen. Hence it is expected that the net dipole moment of is greater than
.
However, has a net dipole moment of 1.46D and
has a net dipole moment of 0.24D. which is greater than $
.
This is because of the direction of the dipole moments of each bond in and
.
The moments of the lone pair in partly cancel out. But in
the resultant moment add up to the bond moment of the lone pair.