| Abstract: | The photochemical decomposition of peroxomonosulfate (PMS) in the presence and absence of 2-propanol at 25°C was found to obey an overall first-order rate – dPMS]/dt = k?PMS]. In the absence of 2-propanol, the quantum yield ≤ for the decomposition of PMS was found to depend upon the concentration of PMS at PMS] > 2 × 10?M, and is independent of concentration at PMS] > 2 × 10?2M. The quantum yield in the presence of 2-propanol was found to be 3.03 at PMS] = 1 × 10?2M and 4.45 at higher concentrations of PMS. In the pH range of 2–9.0 the quantum yield was found to be independent of pH, and the overall rate constant k? was found to be 6.49 × 10?3 s?1 and 1.68 × 10?3 s?1, respectively, in the presence and absence of isopropanol. A suitable chain mechanism is proposed and explained. |
