REDUCTION OF MERCURIC CHLORIDE BY OXALIC ACID IN THE DARK IN PRESENCE OF POTASSIUM PERMANGANATE AS INDUCTOR

The reaction between Hgcl₂ and H₂C₂O₄, induced by KMnO₄, has been studied from the viewpoint of the concentration effect of the inductor on the induction period sod the extent of reduction of mer­curic chloride. The induction period has been found to remain almost constant up to a certain con­centration of KMnO₄, beyond which it gradually goes on increasing till MnO₂ is precipitated when it becomes difficult to ascertain it. By increasing the concentration of the inductor, the reduction of HgCl₂ increases, but its reduction per mole of KMnO₄ at first increases rapidly and then gradually decreases. These ovservations suggest that the reduction of mercuric chloride is brought about through the mechanism of heterogeneous catalysis due to the activation of reacting molecules on the surface of colloidal MnO₂, formed in the KMnO₄-H₂C₂O₄ reaction.