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

Abstract

A study of the two simultaneous equilibria, reactions (1) and (2), has been performed by pulse radiolysis in Ar-saturated aqueous solution at 25°C. The forward and reverse rate constants of equilibrium (2) were determined at 0.3 mol dm^-3 ionic strength to be k₂=(6.1±0.2)×10⁸ and k_-2=(2.1±0.1)×10⁸ d mol^-1 s^-1. These yield the equilibrium constant K₂=k₂/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 reactions of SO₄^- with S₂O₈^2-, t-BuOH and water were found to be <1.5×10³, (7.8±0.2)×10⁵ d mol^-1 s^-1 and (690±120) s^-1, respectively. The relevance of these results to cloud chemistry is discussed.