Chemistry Question on Werner’s Theory of Coordination Compounds

Question

Sum of oxidation state (magnitude) and coordination number of cobalt in $Na[Co(bpy)Cl_4]$ is____ .
(Given : bpy = Sum of oxidation state magnitude and coordination number of cobalt )

Accepted Answer

$Na [Co(bpy)Cl_4]$
Oxidation state of cobalt = $+ 3$
Coordination number of cobalt = $6$
[As bpy is bidentate]
So, sum = $9$
Therefore, the answer is $9$ .