2K3[Fe(CN)6] + 2KOH + Pb(OH)2 → 2K4[Fe(CN)6] + PbO2 + 2H2O
Potassium hexacyanoferrate(III) react with potassium hydroxide and lead(II) hydroxide to produce potassium hexacyanoferrate(II), lead(IV) oxide and water. Potassium hydroxide - diluted solution.