2K3[Fe(CN)6] + 2KOH + H2O2 → 2K4[Fe(CN)6] + O2 + 2H2O
Potassium hexacyanoferrate(III) react with potassium hydroxide and hydrogen peroxide to produce potassium hexacyanoferrate(II), oxygen and water. Hydrogen peroxide - concentrated solution. Potassium hydroxide - diluted solution.