PRODUCTION OF PERCHLORATE AND CHLORITE IONS IN CRYSTALLINE POTASSIUM CHLORATE IRRADIATED WITH COBALT-60 GAMMA RAYS

The production of perchlorate and chlorite ions in crystalline KClO3 irradiated with 60Co γ rays at ca. 30° was demonstrated by infrared absorption measurements. Quantitative determinations of the concentration of ClO4- ions in the solid were performed, and the results were compared with chemical analyses for perchlorate in aqueous solutions of the irradiated solid. The concentrations of ClO4- in solution and in the crystal were found equal within experimental error. Accordingly, the hypothesis that the perchlorate observed in solution was produced by the hydrolysis of Cl2O6 assumed to be present in the solid was unnecessary. Radiolytic yields for the species Cl-, ClO-, ClO2-, and ClO4- were obtained. The concentrations of the first three species appeared to increase linearly with the absorbed dose to a dose as great as 4.4 × 1023 eV (mol of KClO3)-1; the concentration of ClO4- ion, however, increased less rapidly than linearly at large doses. Interesting similarities between the radiolytic and thermal decompositions of the alkali metal chlorates were noted.