This study reevaluates the role of peroxymonosulfate anion radical ((-O3SOO.) or SO5.-) intermediate during radical-induced chain oxidation of HSO3-/SO32- in oxygenated aqueous solution. The SO5.- radical absorption band in the UV is weak: epsilon = 1065 +/- 80 M-1 cm(-1) at lambda (max) (260-265 nm). The SO5.- radical takes part in two radical-radical and four radical-solute reactions, partially producing the other chain carrier, the SO4.- radical, in either case. In this study, employing the pulse-radiolysis technique but adopting a new approach, these two types of reactions of the SO5.- radical have been separately quantified (at room temperature). For example, over pH 3.5-12, the branching ratio of (SO5.- + SO5.-) reactions giving rise to either the SO4.- radical or S2O82- is found to remain similar to 1. The respective reaction rate constants for I --> 0 are (2.2 +/- 0.3) and (2.1 +/- 0.3) x 10(8) M-1 s(-1). The (SO5.- + HSO3-) reactions in acid pH follow two paths, forming the SO4.- radical in one and regenerating the SO3.- radical in the other, with respective rates of ca. (6.0 +/- 0.4) and (3.0 +/- 0.3) x 10(7) M-1 s(-1). In alkaline pH (for SO5.- + SO32- reactions), the rates for similar reactions are ca. (5.6 +/- 0.6) and (1.0 +/- 0.1) x 10(8) M-1 s(-1). From only these results, the earlier prediction of chain length reaching a few thousands could be supported in simulation studies (Bigelow, S. L. Z Phys. Chem. 1898, 28, 493. Young, S. W. J. Am. Chem. Soc. 1902, 24, 297. Titoff, A. Z Phys. Chem. 1903, 45, 641. Backstrom, H. L. J. J. Am. Chem. Soc. 1927, 49, 1460. Alyea, H. N.; Backstrom, H. L. J. J. Am. Chem. Soc. 1929, 51, 90). To explore the feasibility of controlling S(IV) chain oxidation to sulfuric acid in liquid hydrometeors, the effect of radical scavenging on each SOx.-radical (x = 3, 4, 5) was simulated. The results show that for the SO5.- radical a scavenger reactivity of similar to 100 s(-1) may be enough to reduce the chain length by > 98%. However. in the case SO4.- radical scavenging under similar conditions, only similar to 75-80% reduction in acid production was observed. These results suggest a fresh modeling of sulfuric acid generation in atmospheric liquid hydrometeors.