$\mathrm{H}_2 \mathrm{O}_2, \mathrm{ClO}_3^{-}, \mathrm{P}_4, \mathrm{Cl}_2, \mathrm{Cu}^{+1}, \mathrm{NO}_2$
${H_2}\mathop S\limits^{ } {O_4}\,\,\,\,\, \to \,\,\,\,\,\mathop S\limits^{ } {O_2}$
$5{H_2}{O_2} + \,xCl{O_2}\, + 2O{H^ - }\, \to \,xC{l^ - }\, + \,y{O_2} + 6{H_2}O$