Question

The sum of coordination number and oxidation number of the metal $M$ in the complex $\left[M{\left(en\right)}_2\left(C_2{O}_4\right)\right]Cl$ is ________.

Answer 1

Answer: 9

$\left[M(en{)}_2\left(C_2{O}_4\right)\right]Cl$
The complex has two molecules of en and one $C_2{O}_4^{2-}$ ion. Thus, the complex has three bidentate ligands in all. Coordination number
$=2\times$ number of bidentate ligands $=2\times 3=6$ Let the oxidation number of metal ${}^{\ast }{M}^{\prime }$ in the complex be ${}^{\ast }{x}^{\prime }$ The charge on complex ion, en and $C_2{O}_4^{2-}$ are $+1,0$ and $-2$ respectively. Hence, $x+0-2=+1x=3$ The sum of coordination number and oxidation number of the metal $M=6+3=9$