Question

Which of the following molecules has two lone pairs and bond angle (need not be all bond angles) < ${109.5}^{\circ }$?

• A. $S{F}_2$
• B. $Kr{F}_4$
• C. $IO{I}_4^{-}$
• D. All of the above

Answer 1

The correct option is D All of the above

$S{F}_2$, $Kr{F}_4$ and $IO{I}_4^{-}$ have two lone pairs and bond angle (need not be all bond angles) < ${109.5}^{\circ }$.
In $S{F}_2$ molecule, the $S$ atom undergoes $s{p}^3$ hybridization with tetrahedral geometry. Due to repulsion between the bond pair and lone pair of electrons the bond angle decreases from tetrahedral value.
In $Kr{F}_4$ molecule, the central $Kr$ atom undergoes $s{p}^3{d}^2$ hybridization with octahedral geometry. The bond angle is ${90}^o$.
In $IO{I}_4^{-}$ ion, the $I$ atom undergoes $s{p}^3{d}^2$ hybridization with octahedral geometry. The bond angle is ${90}^o$.