Correct increasing order for the wavelength of absorption in the visible region for the complexes of `Co^(3+)` is:

Options

A. `[Co(e n)_3]^(3+), [Co(NH_3)_6]^(3+) , [Co(H_2O)_6]^(3+) `
B. ` [Co(H_2O)_6]^(3+), [Co(e n)_3]^(3+), [Co(NH_3)_6]^(3+) , `
C. ` [Co(H_2O)_6]^(3+), [Co(NH_3)_6]^(3+) , [Co(e n)_3]^(3+) `
D. ` [Co(NH_3)_6]^(3+) , [Co(e n)_3]^(3+) , [Co(H_2O)_6]^(3+)`

Answer

A

Explanation

Strength of ligands attached with `Co^(3+)` ion is in the order of `e n gt NH_3 gt H_2O` . So order of splitting (value of ) 0∆ will be in the same order.
Wavelength absorbing light `prop (1)/(Delta_0)`