X‐ray photoelectron spectroscopic studies of the heterogenous reaction of gaseous nitric acid with sodium chloride: Kinetics and contribution to the chemistry of the marine troposphere

Abstract

We report here the first measurement of the reaction probability (ϕ) at 298 K for the reaction (1) HNO 3(g) + NaCl (s) → HCl (g) + NaNO 3(s) , ϕ = (4±2) × 10 −4 , which was determined using X‐ray photoelectron spectroscopy to follow the formation of nitrate on the surface of single crystals of NaCl. Along with recent kinetic data for the reaction N 2 O 5(g) + NaCl (s) → ClNO 2(g) + NaNO 3(s) , we show that in the dark with typical relative concentrations of N 2 O 5 and HNO 3 , the N 2 O 5 reaction should be competitive with, and may exceed, that of HNO 3 . The reactions of NO 2 and ClONO 2 with NaCl are expected to be much less important. Thus, the tropospheric production of chlorine atoms via photolysis of ClNO 2 from the N 2 O 5 reaction is anticipated, which has the potential to impact the ozone balance in the troposphere.