When $KMnO_4$ is reduced with oxalic acid in acidic solution,the oxidation number of $Mn$ changes from

What is the oxidation state of $Fe$ in $Fe_{0.94}O$?

In the chromyl chloride test,the oxidation state of $Cr$ changes from:

The oxidation number of oxygen in an $O_2$ molecule is:

Calculate the oxidation number of sulfur,chromium,and nitrogen in $H_2SO_5$,$Cr_2O_7^{2-}$,and $NO_3^-$. Suggest the structures of these compounds and explain the fallacy in the direct calculation of the oxidation number for $H_2SO_5$.

What is the oxidation number of Carbon in $K_{2}C_{2}O_{4}$?