Among the following, the pair in which the two species are not isostructural is
- SiF4 and SF4
- IO3- and XeO3
- BH4- and NH4+
- PF6- and SF6
Answer
(1) SiF4 and SF4
Solution
(1) SiF4: 4 bp + 0 lp ⇒ sp3, tetrahedral; SF4: 4 bp + 1 lp ⇒ sp3d, see-saw ⇒ not isostructural.
(2) IO3- and XeO3: 3 bp + 1 lp each ⇒ trigonal pyramidal.
(3) BH4- and NH4+: 4 bp each ⇒ tetrahedral.
(4) PF6- and SF6: 6 bp each ⇒ octahedral.
Answer: (1)