Studies of reactions of importance in the stratosphere. IV. Rate constant for the reaction Cl+HOClrarr;HCl+ClO over the temperature range 243ndash;365 K

摘要

The title reaction was studied over the temperature range 243ndash;365 K using the discharge flow technique with mass spectrometry for detection. The rate constant was measured by detecting the loss of HOCl in the presence of a large excess of chlorine atoms. The resulting temperature dependent rate constant is given bykquest;0.5)times;10minus;12explsqb;minus;(130plusmn;60)/Trsqb; cm3thinsp;moleculeminus;1thinsp;sminus;1, where the stated errors include our estimate of the maximum possible systematic error. This reaction becomes a significant pathway to HCl in the stratosphere when the total ClX exceeds 10 ppbv. Upper limits for rate constants for the reactions HOCl+NOrarr;products and HOCl+O3rarr;products at 300 K were established to be 1.0times;10minus;17and 4.0times;10minus;16cm3thinsp;moleculeminus;1thinsp;sminus;1, respectively.