Barium ions, `CN^(-) and Co^(2+)` form an ionic complex.If this complex is 75% ionised in aqueous solution with Vant Hoff factor (i) equal to four and paramagnetic moment is found to be 1.73 BM (due to spin only) then the hybridisation state of Co (II) in the complex will be :

Options

A. `sp^3d`
B. `d^2sp^3`
C. `sp^3d^2`
D. `dsp^3`

Answer

D

Explanation

`{:(Ba_(alpha-2)[Co(CN)_x]_2 to,(x-2) Ba^(2+),+2[Co(CN)_x]^(-(x-2))),(1-alpha,(x-2)alpha, " " 2alpha):}`
`i=1-alpha+xalpha-2alpha+2alpha`
`(x-1)alpha=3 " " x-1=3/alpha`
`alpha=0.75 , " " x=5`
`:.` formula of complex is `Ba_3[Co(CN)_5]_2` and hybridisation is `dsp^3` as it is a inner orbital complex with strong field ligand