Identify the molecule among the following that exhibits a non-zero dipole moment and has a square pyramidal geometry.

Solution

1. The central atom $\text{I}$ in ${\text{IF}}_5$ has 7 valence electrons and forms 5 bonds with $\text{F}$ atoms.
2. The steric number is $5 + 1 = 6$, corresponding to $s{p}^3{d}^2$ hybridization.
3. With 5 bonding pairs and 1 lone pair, the geometry is square pyramidal.
4. Due to the lone pair, the molecule is polar and has a non-zero dipole moment.
5. Hence the answer is (B).