Looking for classes? Ksquare Career Institute, Bengaluru →
Which one of the following pairs is isostructural (i.e. having the same shape and hybridization)?
A
[$BF_4^-$ and $NH_4^+$]
B
[$BCl_3$ and $BrCl_3$]
C
[$NH_3$ and $NO_3^-$]
D
[$NF_3$ and $BF_3$]
Detailed Solution
$BF_4^-$: 4 bond pairs, no lone pair, $sp^3$, tetrahedral. $NH_4^+$: 4 bond pairs, no lone pair, $sp^3$, tetrahedral. Same shape and hybridisation.
$BCl_3$ is $sp^2$ trigonal planar, but $BrCl_3$ is $sp^3d$ T-shaped.
$NH_3$ is $sp^3$ pyramidal, but $NO_3^-$ is $sp^2$ trigonal planar.
$NF_3$ is $sp^3$ pyramidal, but $BF_3$ is $sp^2$ trigonal planar.
So $BF_4^-$ and $NH_4^+$ are isostructural.
$BCl_3$ is $sp^2$ trigonal planar, but $BrCl_3$ is $sp^3d$ T-shaped.
$NH_3$ is $sp^3$ pyramidal, but $NO_3^-$ is $sp^2$ trigonal planar.
$NF_3$ is $sp^3$ pyramidal, but $BF_3$ is $sp^2$ trigonal planar.
So $BF_4^-$ and $NH_4^+$ are isostructural.