KINETICS OF THE REACTION BETWEEN HEXAVALENT CHROMIUM AND OXALATE, CATALYSED BY MANGANOUS SULPHATE

The reaction between hexavalent chromium and oxalate has been specially studied in presence of manganous sulphate, which acts as a catalyst for the system. The temperature coefficient and the heat of activation for the catalysed reaction are calculated to be 2.932 and 19890 cals. respectively against the values 1.915 and 11995 cals. for the uncatalysed system. The order of the reaction in pre­ence of manganous sulphate tends to become unimolecular whilst without manganous sulphate it appears as trimolecular. These results suggest a change in the reaction mechanism in the presence of bivalent manganese.