Efficient bulk mass accommodation and dissociation of N2O5 in neutral aqueous aerosol
- 1Laboratory of Environmental Chemistry, Paul Scherrer Institut, Villigen, 5232, Switzerland
- 2Department of Chemistry and Biochemistry, University of Bern, Bern, 3012, Switzerland
- 3Laboratory of Radiochemistry, Paul Scherrer Institut, Villigen, 5232, Switzerland
Abstract. An isotope exchange experiment with the short-lived radioactive tracer 13N is used to trace N2O5 uptake into nitrate-containing aqueous aerosol particles. While uptake of 13N-labelled N2O5 to deliquesced Na2SO4 aerosol is consistent with previous studies, efficient exchange of labelled nitrate with the non-labelled nitrate pool was observed in the presence of aerosol-phase nitrate. The experiments provide direct evidence for efficient bulk mass accommodation of N2O5 into aqueous solution with αb > 0.4 at room temperature, as well as for the fast dissociation into nitronium and nitrate. While for experimental reasons this study is limited to non-acidic nitrate-containing aerosol, it is likely that bulk mass accommodation and dissociation are not limiting N2O5 uptake under wider ranges of conditions.