Chemistry - Redox Reactions Question with Solution | TestHub

The complex is$\left[\mathrm{C}\mathrm{r}\right({\mathrm{O}}_2\left)\right(\mathrm{N}{\mathrm{H}}_3{)}_4{\mathrm{H}}_2\mathrm{O}]\mathrm{C}{\mathrm{l}}_2$, let oxidation number of oxygen is x
So$+3+2\mathrm{x}+0\times 4+0-2=0$
$2\mathrm{x}=-1$
$\mathrm{x}=-\frac{1}{2}$.
Hence, oxygen is in superoxo form$\left({\mathrm{O}}_2^{-}\right)$.