Question

Among the following species, which pairs are not isostructural
$N{F}_3,N{O}_3^{-},B{F}_3,H_3{O}^{+},H{N}_3$

• A. $[N{F}_3,N{O}_3^{-}]and[B{F}_3,H_3{O}^{+}]$
• B. $[N{F}_3,H{N}_3]and[N{O}_3^{-},B{F}_3]$
• C. $[N{F}_3,H_3{O}^{+}]and[N{O}_3^{-},B{F}_3]$
• D. $[N{F}_3,H_3{O}^{+}]and[H{N}_3,B{F}_3]$

Answer 1

Answer: (A), (B), (D)

$[N{F}_3,H_3{O}^{+}]and[H{N}_3,B{F}_3]$

(a) $B{F}_3$ is $s{p}^2$ hybridised with planar shape and $H_3{O}^{+}$ is $s{p}^3$ hybridized with trigonal pyramidal shape. Hence, non isostrucutral.
(b) $N{F}_3$ is $s{p}^3$ hybridised with trigonal pyramidal shape. $N_{3}H$ is $sp$ is hybridised and linear in shape. Hence, non isostrucutral.
(c) $N{F}_3,H_3{O}^{+}$ are $s{p}^3$ hybridized with trigonal pyramidal shape. $N{O}_3^{-},B{F}_3$ are planar with $s{p}^2$ hybridised. Hence, these are isostructural pairs.
(d) $N_{3}H$ is $sp$ hybridised and linear in shape whereas $B{F}_3$ is $s{p}^2$ hybridised with planar shape. Hence, not isostrucutral.