Question

The Shape Of ${{\mathrm{ClO}}_3}^{-}$ According To VSEPR Model Is

• A. Pyramidal
• B. Tetrahedral
• C. Square planar
• D. Planar triangle

Answer 1

The correct option is A

Pyramidal

Explanation for correct option:

A. Pyramidal

Step 1: Hybridization:

• “Hybridization is defined as the process of intermixing of the orbitals of slightly different energies so as to redistribute their energies, resulting in the formation of a new set of orbitals of equivalent energies and shape.”

Step 2: Formula used for calculation:

• $\mathrm{Steric}\mathrm{number}=\frac{1}{2}\left[\mathrm{V}+\mathrm{M}-\mathrm{C}+\mathrm{A}\right]$
• Where V is the number of valence electrons, M is the monovalent electron, C is the positive charge and A represents the negative charge.

Step 3: Calculation for Hybridisation of ${{\mathrm{ClO}}_3}^{-}$:

• The total number of valence electrons of Chlorine in ${{\mathrm{ClO}}_3}^{-}$ is 7 and there is no monovalent atom.
• $$\begin{gathered} \mathrm{Steric}\mathrm{number}=\frac{1}{2}\left[7+1\right] \\ \mathrm{Steric}\mathrm{number}=\frac{1}{2}\times 8=4 \end{gathered}$$
• The steric number is 4, thus the hybridization of ${{\mathrm{ClO}}_3}^{-}$ is ${\mathrm{sp}}^3$.

Step 4: Shape of ${{\mathrm{ClO}}_3}^{-}$:

• In ${{\mathrm{ClO}}_3}^{-}$, there is one lone pair of electrons and three bond pairs. Thus as per VSEPR theory, the shape of ${{\mathrm{ClO}}_3}^{-}$ is pyramidal shape.
• The structure of ${{\mathrm{ClO}}_3}^{-}$ is given below: