Gas phase reactions of HNO_3 with Cl~-, Cl~-H_2O, and Cl~-HCl, of Cl_2 with Cl~-H_2O and Cl~-HCl, and of HCl with Cl~-H_2O

摘要

This paper reports on the gas phase reactions of HNO_3 with Cl~-, Cl~-H_2O, and Cl~-HCl, of Cl_2 with Cl~-H_2O and Cl~-HCl, and of HCl with Cl~-H_2O. Rate constants and product ions have been determined at room temperature and at low pressures (0.7-1.7 mb) by means of a flow tube reactor coupled to a quadrupole mass spectrometer. Apart from Cl~-HCl + Cl_2, all reactions proceed at the collision rate. The reaction mechanism for all reactions, except for Cl~- + HNO_3, seems to be ligand switching. The implication of the results on a chemical ionisation method for the in situ derivation of stratospheric nitric acid concentrations is discussed.