In which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three ?
- SF4
- I3-
- SbCl52-
- PCl5
Answer
(3) SbCl52-
Solution
Steric number = σ bonds + lone pairs on the central atom.
SF4: 4 + 1 = 5 ⇒ sp3d
I3-: 2 + 3 = 5 ⇒ sp3d
PCl5: 5 + 0 = 5 ⇒ sp3d
SbCl52-: Sb has 5 valence electrons + 2 (charge) = 7; 5 used in bonds, so 1 lone pair
⇒ 5 + 1 = 6 ⇒ sp3d2 (square pyramidal)
∴ SbCl52- differs from the other three.
Answer: (3)