Question

Which of the following is a polar molecules?

• A. $B{F}_3$
• B. $S{F}_4$
• C. $Si{F}_4$
• D. $Xe{F}_4$

Answer 1

The correct option is B $S{F}_4$

$B{F}_3$, $Si{F}_4$ and $Xe{F}_4$ are non polar molecules as individual bond dipoles cancel each other.
$S{F}_4$ is a polar molecule as the individual bond dipoles do not cancel each other.
$S{F}_4$ contains $4$ bond pairs of electrons and $1$ lone pair of electrons. $S$ atom undergoes $s{p}^{3}d$ hybridization which results in distorted tetrahedral geometry.
$B{F}_3$ contains $3$ bond pairs of electrons and zero lone pair of electrons. $B$ atom undergoes $s{p}^2$ hybridization which results in trigonal planar geometry.,
$Si{F}_4$ contains $4$ bond pairs of electrons and zero lone pairs of electrons. $Si$ atom undergoes $s{p}^3$ hybridization which results in tetrahedral geometry.
$Xe{F}_4$ contains $4$ bond pairs of electrons and $2$ lone pairs of electrons. $Xe$ atom undergoes $s{p}^3{d}^2$ hybridization which results in square planar geometry.