Question

In which of the following octahedral complexes of Co (At. no. 27), will the magnitude of Δ_o be the highest?

(a) [Co(NH₃)₆]³⁺ 

(b) [Co(CN)₆]^3–

(c) [Co(C₂O₄)₃]^3– 

(d) [Co(H₂O)₆]³⁺

Answer 1

Correct option(b) [Co(CN)₆]^3–

Explanation:

CFSE (crystal field spitting energy) for octahedra, complex, Δ_o depends on on the strength of negative ligand. Spectrochemically, it has been found that the strength of splitting as follows