Chemistry - Redox Reactions Question with Solution | TestHub

${\mathrm{H}}_2{\mathrm{O}}_2^{-1}$${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3^{+4}$$\stackrel{+3}{\mathrm{H}\mathrm{N}{\mathrm{O}}_2}$
As in${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4$phosphorous is in maximum oxidation state +5 so it can not undergo oxidation or can be reduced only so it is an oxidant only.