Which of the following molecules is non-polar despite having polar bonds?

Solution

1. ${\text{XeF}}_4$ has $4$ bonding pairs and $2$ lone pairs, resulting in a square planar geometry.
2. In a square planar geometry, the dipole moments of the four $\text{Xe}-\text{F}$ bonds cancel out.
3. ${\text{SF}}_4$ is a see-saw molecule and is polar.
4. ${\text{IF}}_5$ is square pyramidal and is polar.
5. Hence the answer is (B).