THE UPTAKE OF N2O5 ONTO SMALL SULFURIC-ACID PARTICLES

The probabilities for N2O5 loss onto sulfuric acid aerosol (60-80 wt% H2SO4, 0.1-0.2 um radius, 230-300K) were measured using a laminar flow reactor coupled to a sulfuric acid aerosol source and a chemical ionization mass spectrometer. The aerosol morphology was extracted from measurements of the aerosol extinction of ultraviolet light (200-370nm) by using Mie theory. The reaction probabilities, gamma, are large (0.06-0.12) and are comparable to probabilities measured previously under similar conditions on bulk sulfuric acid surfaces and small aerosol. These measurements confirm that the overall reaction of N2O5 with H2O in/on 60-80% sulfuric acid is fast and the uptake is due to loss very close to the liquid surface.