question_answer

Which one of the following pairs is isostructural (i.e., having the same shape and hybridization)?

A) \[\text{ }\!\![\!\!\text{ BC}{{\text{l}}_{\text{3}}}\,\text{and}\,\text{BrC}{{\text{l}}_{\text{3}}}\text{ }\!\!]\!\!\text{ }\]           

B)   \[\text{ }\!\![\!\!\text{ N}{{\text{H}}_{\text{3}}}\,\text{and}\,\text{NO}_{\text{3}}^{\text{-}}\text{ }\!\!]\!\!\text{ }\]

C)        \[\text{ }\!\![\!\!\text{ N}{{\text{F}}_{\text{3}}}\,\text{and}\,\text{B}{{\text{F}}_{\text{3}}}\text{ }\!\!]\!\!\text{ }\]           

D)   \[\text{ }\!\![\!\!\text{ BF}_{\text{4}}^{\text{-}}\,\text{and}\,\text{NH}_{\text{4}}^{\text{+}}\text{ }\!\!]\!\!\text{ }\]

Correct Answer: C

Solution :

If number of bond pairs and lone pairs are same for the given pairs, they are is structural. \[BC{{l}_{3}}\]and\[BrC{{l}_{3}}\] \[N{{H}_{3}}\,\text{and}\,NO_{3}^{-}\] \[N{{F}_{3}}\,\text{and}\,BF_{3}^{{}}\] \[BF_{4}^{-}\,\text{and}\,NH_{4}^{+}\] Thus, \[BF_{4}^{-}\,\text{and}\,NH_{4}^{+}\]are isostructural.