Gas phase reactions of HNO3 with cl(-), Cl-H2O, and Cl-HCl, of Cl-2 with Cl-H2O and Cl-HCl, and of HCl with Cl-H2O

This paper reports on the gas phase reactions of HNO3 with Cl-, Cl-H2O, and Cl-HCl, of Cl-2 with Cl-H2O and Cl-HCl, and of HCl with Cl-H2O. Rate const ants and product ions have been determined at room temperature and at low p ressures (0.7-1.7 mb) by means of a flow tube reactor coupled to a quadrupo le mass spectrometer. Apart from Cl-HCl + Cl-2, all reactions proceed at th e collision rate. The reaction mechanism for all reactions, except for Cl- + HNO3, seems to be ligand switching. The implication of the results on a c hemical ionisation method for the in situ derivation of stratospheric nitri c acid concentrations is discussed. (Int J Mass Spectrom 181 (1998) 113-121 ) (C) 1998 Elsevier Science B.V.