Ry. Zhang et al., VAPOR-PRESSURE MEASUREMENTS FOR THE H2SO4 HNO3/H2O AND H2SO4/HCL/H2O SYSTEMS - INCORPORATION OF STRATOSPHERIC ACIDS INTO BACKGROUND SULFATEAEROSOLS/, Journal of physical chemistry, 97(32), 1993, pp. 8541-8548
Vapor pressures over aqueous H2SO4/HNO3/H2O and H2SO4/HCl/H2O solution
s have been measured for sulfuric acid contents ranging from 35 to 75
wt % at temperatures between 190 and 230 K. From the data, the Henry's
law solubility constants for both systems are determined, and the equ
ilibrium compositions of aqueous stratospheric aerosols are predicted
as a function of ambient temperature and mixing ratios of H2O and HNO3
. The results indicate that, at the low temperatures characteristic of
the stratosphere at high latitudes in the winter and spring, the HNO3
content reaches levels of the order of 10 wt % in the background sulf
ate aerosols. The results also indicate that the amount of dissolved H
Cl in the background sulfate aerosols is small when compared with diss
olved HNO3 but may be significant for the production of Cl2 via the he
terogeneous reaction between ClONO2 and HCl at low temperatures.