Question

Which of the following pairs are not isostructural?

• A. $N{H}_3,C{H}_3^{-}$
• B. $Xe{F}_4,Xe{O}_4$
• C. $SiC{l}_4,PC{l}_4^{+}$
• D. Diamond, silicon carbide

Answer 1

The correct option is B $Xe{F}_4,Xe{O}_4$

Isostructural species are those which have the same shape as well as same hybridisation.
In option $\left(a\right)$, they both have the same hybridisation i.e., $s{p}^3$ as well as the same shape i.e., pyramidal. Hence, these are isostructural.

In option $\left(b\right)$, $Xe{F}_4$ has a square planar shape and $Xe{O}_4$ is tetrahedral. So, they are not isostructural.In option $\left(c\right)$, both have the same hybridisation i.e., $s{p}^3$ and the same structure i.e. tetrahedral. Hence, these are isostructural.

In option $\left(d\right)$, both are giant covalent structures with the same hybridisation i.e., $s{p}^3$ and tetrahedral geometry. Hence, these are isostructural.