Barium ion , `CN^(-)` and `Co^(2+)` form an ionic complex . If that complex is supposed to be `75%` ionised in water with van't Hoff factor `'i'` equal to four , then the coordination number of `Co^(2+)` in the complex can be :

Options

A. 6
B. 4
C. `6 & 4` both possible
D. 5

Answer

4

Explanation

`alpha=(i-1)/(x xx1)=(3)/(4)=(4-1)/(x-1)" ":.x=5" ":." "` Complex is `Ba_(3)[Co(CN)_(5)]_(2)`