The oxidation state of each oxygen atom in $Na_{2}O_{2}$ is

What is the oxidation state of chlorine atom in chloric acid?

Sulphur has the highest oxidation state in

Which one of the following does not have an underlined atom with a fractional oxidation state?

Calculate the oxidation number of sulphur,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 calculated oxidation number for $H_2SO_5$.

What is the oxidation number of $Mn$ in $MnO_4^{-}$?