Answer:
Consider a complex [Fe(CN)6]−3
CN is a powerful field ligand and uses inner 3d-orbitals to form a low spin complex. Because there are 6 ligands, it has octahedral geometry. So the hybridization of the complex is d2sp3.
The electronic configuration of central metal ion Fe is
Fe (26) = [Ar] 4s2 3d6
Fe3+ = [Ar] 3d5 4s0
The central metal has an oxidation number +3 calculated as:
x + 6 × (−1) = −3
(1) Hybridization – d2sp3
(2) Magnetic behaviour – Paramagnetic in nature
(3) The oxidation state of Fe = -3