Hydrolysis of N{sub 2}O{sub 5} and ClONO{sub 2} on the H{sub 2}SO{sub 4}/HNO{sub 3}/H{sub 2}O ternary solutions under stratospheric conditions
The reaction probabilities of N{sub 2}O{sub 5} and ClONO{sub 2} with H{sub 2}O on liquid sulfuric acid surfaces have been reexamined to determine the effect of HNO{sub 3} on these two hydrolysis rates, using a fast flow reactor coupled to a chemical ionization mass spectrometer. The measurements were carried out by maintaining constant H{sub 2}O and HNO{sub 3} partial pressures and by varying temperatures between 227 and 195 K in order to mimic compositions representative of stratospheric aerosols. For experiments excluding HNO{sub 3}, the reaction probability of N{sub 2}O{sub 5} hydrolysis was found to be near 0.1, independent of temperature and H{sub 2}SO{sub 4} content. This is in agreement with results previously measured under similar conditions. In the presence of gaseous HNO{sub 3} at stratospheric concentrations, the reaction probability was observed to decrease from about 0.09 at 218 K to about 0.02-0.03 at 195 K for P{sub H20} = 3.8x10{sup {minus}4}-1.0x10{sup {minus}3} Torr, showing that incorporation of HNO{sub 3} into liquid sulfuric acid greatly retarded the N{sub 2}O{sub 5} hydrolysis. The ClONO{sub 2} reaction with H{sub 2}O on liquid sulfuric acid, on the other hand, did not appear to be affected by the presence of HNO{sub 3}. 22 refs., 3 figs.
- OSTI ID:
- 166793
- Journal Information:
- Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 12 Vol. 22; ISSN GPRLAJ; ISSN 0094-8276
- Country of Publication:
- United States
- Language:
- English
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