Question

Oxidation state of $Cr$ in $K_3\left[Cr\right(C_2{O}_4{)}_3]$ is :

Answer 1

Let $x$ be the oxidation state of $Cr$ in $K_3\left[Cr\right(C_2{O}_4{)}_3]$.
Since, the overall charge on the complex is $0$, the sum of oxidation states of all elements in it should be equal to $0$.
Therefore,
$+3+x+3(-2)=0$
or, $x=+3$.
Hence,
the oxidation state of $Cr$ in $K_3\left[Cr\right(C_2{O}_4{)}_3]$ is $+3$.