Abstract This paper analyzed the different phenomena produced by reactions between sodium sulfide and potassium permanganate with different drop adding sequence, dosage and pH. Under acidic conditions:MnO4- was reduced to Mn2+, S2- was oxidized to SO42-, and higher concentrations of MnO4- reacting with Mn2+ produced brown MnO2 precipitation, with the addition of Na2S solution, the reaction system was from acidic to alkaline, Mn2+ transformed into white Mn(OH)2 precipitate. In strong alkaline conditions:flesh red precipitation MnS was observed, but added more concentrated KMnO4 solution to lower concentrations of Na2S solution, pale yellow precipitate S was observed, when added extremely dilute KMnO4 solution there was no phenomenon.
