The oxidation state of $Cr$ in $K_{2}Cr_{2}O_{7}$ is

In alkaline condition,$KMnO_4$ reacts as $2KMnO_4 + 2KOH \to 2K_2MnO_4 + H_2O + [O]$. The equivalent weight of $KMnO_4$ would be (Atomic mass of $K = 39$,$Mn = 55$,$O = 16$).

The oxidation states of sulfur atoms and the number of $S-OH$ bonds in Peroxydisulfuric acid are respectively:

Which of the following is $NOT$ correct for $C_3O_2$?

What is the oxidation number of $N$ in $HNO_4$?

Identify the process in which the change in the oxidation state is $5$: