Nas reações

NO!$ underset{3}{-} !$ + 4H⁺ + 3e⁻ !$ ↔ !$NO + 2H₂O E !$ underset{red}{0} !$= + 0,96v

Cr₂ O!$ underset{7}{2-} !$ + 14H⁺ + 6e⁻ !$ ↔ !$2Cr³⁺ + 7H₂O E !$ underset{red}{0} !$ = + 1,33v

MnO !$ underset{4}{-} !$ + 8H⁺ + 5e⁻ !$ ↔ !$ Mn²⁺ + 4H₂O E !$ underset{red}{0} !$ = + 1,51v ,

o poder redutor MnO!$ underset{4}{-} !$ /H⁺ >cr₂O!$ underset{7}{2-} !$ /H⁺ > NO!$ underset{3}{-} !$ /H⁺