Question

In which of the following coordination entities the magnitude
∆₀ (CFSE in octahedral field) will be maximum?
(a) [Co(H₂O)₆]³⁺ (b) [Co(NH₃)₆]³⁺
(c) [Co(CN)₆]³⁻ (d) [Co (C₂O₄)₃]³⁻
(At. No. Co = 27)

Answer 1

Answer:

In which of the following coordination entities the magnitude

∆₀ (CFSE in octahedral field) will be maximum?

(a) [Co(H₂O)₆]³⁺

(b) [Co(NH₃)₆]³⁺

(c) [Co(CN)₆]³⁻

(d) [Co (C₂O₄)₃]³⁻

(At. No. Co = 27)

Answer 2

The magnitude ∆₀ (CFSE in octahedral field) would be maximum in :

• There is one factor that determines the magnitude of splitting. i.e Strength of radical or ion attached to central metal atom.

• When strong field radical or ion is attached to central atom, splitting would be large in magnitude and vice versa.

• We can see that central atom in all four options is same. i.e Co

• We have following different radical or ion,

a) H₂O, b) NH₃, c) CN- and d) C₂O₄^2-

• Strength order is given below :

C₂O₄^2- < H₂O < NH₃ < CN-

• CN- is the strongest among all, Hence [Co(CN)₆]³⁻ will have the maximum magnitude in ∆₀ (CFSE in octahedral field)