Ncert Exercises & Solutions

Among the given species the isostructural pair is :

1. $[{NF}_{3} and {BF}_{3}]$

2. $[{BF}_{4}^{-} and {NH}_{4}^{+}]$

3. $[{BCl}_{3} and {BrCl}_{3}]$

4. $[{NH}_{3} and {NO}_{3}^{-}]$

HINT: Isostructural species are those which have the same shape and hybridization.

Explanation:

1.) NF₃ is pyramidal whereas BF₃ is trigonal planar. Hence, both have different shapes.

2.)

{BF}_{4}^{-}

and

{NH}_{4}^{+}

ions both are tetrahedral. Both have the same shape and the hybridization is also the same, that is,

{sp}^{3}

3.) BCl₃ is trigonal planar whereas BrCl₃ is trigonal bipyramidal. Both have different same shapes.

4.) NH₃ is pyramidal whereas

{NO}_{3}^{-}

is trigonal planar. Both have different shape.

Hence, option second is the correct answer.