In which of the following order the given complex ions are arranged correctly with respect to their decreasing spin only magnetic moment? (i) FeF 6 3 - (ii) Co NH 3 6 3 + (iii) NiCl 4 2 - (iv) Cu NH 3 4 2 +

Step-by-step solution

Complex (i) FeF 6 3 - Fe 3 + ⇒ [ Ar ] 3   d 5 ,   F - is WFL n = 5 ,    μ = 35   B . M (ii) Co NH 3 6 3 + ⇒ Co 3 + Ar 3   d 6 , NH 3 is SFL n = 0 ,   μ = 0   B . M (iii) NiCl 4 2 - Ni 2 + ⇒ Ar 3   d 8 , Cl - → WFL n = 2 ,   μ = 8   B . M (iv) Cu NH 3 4 2 + Cu 2 + ⇒ Ar 3   d 9 , NH 3 → SFL n = 1 ,   μ = 3   B . M Thus correct order of spin only magnetic moment is ( i ) > ( iii ) > ( i