In which one of the following species the central atom has the type of hybridisation which is not the same as that present in the other three?

Solution :
Key Idea Molecules having same hybridisation have same number of hybrid orbitals,
$$H = \frac{1}{2}\left[ {V + X - C + A} \right]$$
where,
$$V = $$  number of valence electrons of central atom
$$X = $$  number of monovalent atoms
$$C = $$  charge on cation
$$A = $$  charge on anion
$$\eqalign{ & SbCl_5^{2 - } = s{p^3}{d^2},PC{l_5} = s{p^3}d \cr & S{F_4} = s{p^3}d,l_3^ - = s{p^3}d \cr} $$