Question

The shape of $Cl{O}_3^{-}$ is

• A. Trigonal planar
• B. Pyramidal
• C. Tetrahedral
• D. Square planar

Answer 1

The correct option is B Pyramidal

To calculate hybridisation, we can use the formula
$\frac{1}{2}(V+M-C+A)$
Here,
$V=\text{Number of valence electrons}$
$M=\text{Number of monovalent atom}$
$C=\text{Magnitude of positive charge}$
$A=\text{Magnitude of negative charge}$
Here, the central atom, $Cl$ has $7$ valence electrons. Thus
$\frac{1}{2}(7+0-0+1)=4$
Hence in $Cl{O}_3^{-}$ the central atom $Cl$ is $s{p}^3$ hybridised and has one lone pair.
So its shape is pyramidal.