Question

Which of the following molecules has the maximum dipole moment?

(a) ${CO}_2$

(b) ${CH}_4$

(c) ${NH}_3$

(d) ${NF}_3$

Answer 1

In ${NH}_3, {H}$ is less electronegative than ${N}$ and hence dipole moment of each ${N}-{H}$ bond is towards ${N}$ and create high net dipole moment whereas in ${NF}_3, {~F}$ is more electronegative than ${N}$, the dipole moment of each ${N}-{F}$ bond is opposite to that of lone pair hence, reducing the net dipole moment.