Abstract Aiming at some questions in the properties experiment of inorganic chemistry about the influence of solution pH on the redox reaction products between potassium permanganate and sodium sulfite, the chemical phenomenon changes after the reaction products being placed for a period of time, etc., the functions between electrode potential of related redox couples & pH were derived by Nernst equation, and the thermodynamic stability and existence forms of Mn system related substances in water were discussed by potential-pH diagram. The reasons for the reaction of KMnO4 as oxidant with Na2SO3 to produce different products under different pH were discussed. In addition, the possibility of the products being converted into MnO2 , Mn(OH)2, etc., by placing for a period of time was discussed theoretically under certain pH condition and the excess of some reactants.
ZHANG Wei, MA Li, WANG Yu-Ling, WEI Xiao, CHEN Hong-Jin. Application of Potential-pH Diagram in Judging Reaction Products of Potassium Permanganate[J]. Chinese Journal of Chemical Education, 2023, 44(2): 125-129.
