Question

What is the shape of ${\mathrm{ClF}}_5$ using VSEPR Theory?

Answer 1

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 ${\mathrm{ClF}}_5$:

• The total number of valence electrons of chlorine in ${\mathrm{ClF}}_5$ is 7 and there are 5 monovalent atoms.
• $$\begin{gathered} \mathrm{Steric}\mathrm{number}=\frac{1}{2}\left[7+5\right] \\ \mathrm{Steric}\mathrm{number}=\frac{1}{2}\times 12=6 \end{gathered}$$
• The Steric number is 6, thus the hybridization of ${\mathrm{ClF}}_5$ is ${\mathrm{sp}}^3{\mathrm{d}}^2$.

Step 4: Shape of ${\mathrm{ClF}}_5$:

• As per VSEPR, the shape for ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridization is square pyramidal with asymmetric charge distribution around the central atom.
• The structure of ${\mathrm{ClF}}_5$is given below:

Thus, the shape of ${\mathrm{ClF}}_5$ is square pyramidal.