The reactivity of chlorine atoms in aqueous solution - Part II. The equilibrium SO4.-+Cl-reversible arrow Cl-.+SO42-

A study of the two simultaneous equilibria, reactions (1) and (2), has been performed by pulse radiolysis in Ar-saturated aqueous solution at 25 degre es C. [GRAPHICS] The forward and reverse rate constants of equilibrium (2) were determined a t 0.3 mol dm(-3) ionic strength to be k(2) = (6.1 +/- 0.2) x 10(8) and k(-2 ) = (2.1 +/- 0.1) x 10(8) dm(3) mol(-1) s(-1). These yield the equilibrium constant K-2 = k(2)/k(-2) = (2.9 +/- 0.2) at 0.3 mol dm(-3) ionic strength, or 1.2 corrected to zero ionic strength. As part of the study, the reactio ns of SO4.- with S2O82-, t-BuOH and water were found to be < 1.5 x 10(3), ( 7.8 +/- 0.2) x 10(5) dm(3) mol(-1) s(-1) and (690 +/- 120) s(-1), respectiv ely. The relevance of these results to cloud chemistry is discussed.