5H4P2O6 + 2KMnO4 + 3H2SO4 + 2H2O → 10H3PO4 + 2MnSO4 + K2SO4
Hypophosphoric acid react with potassium permanganate, sulfuric acid and water to produce phosphoric acid, manganese(II) sulfate and potassium sulfate. Hypophosphoric acid - concentrated solution. Sulfuric acid - diluted solution.