\(Na [Co(bpy)Cl_4]\)
Oxidation state of cobalt = \(+ 3\)
Coordination number of cobalt = \(6\)
[As bpy is bidentate]
So, sum = \(9\)
Therefore, the answer is \(9\).
In 1893 Werner produced a theory to explain the structures, formation and nature of bonding in the coordination compounds. This theory is known as Werner’s theory of coordination compounds.
The important postulates as observed by Alfred Werner throughout his experiments are as follows: