Gas- and aqueous-phase chemistry of HO/sub 2/ in liquid water clouds
A model for reversible mass transport of HO/sub 2/ between the gas and aqueous phases of liquid water clouds is used to examine the coupling of reaction kinetics of this species in the two phases. The Henry's law coefficient of HO/sub 2/ necessary for this analysis is evaluated by means of a thermochemical cycle involving O/sup -//sub 2/(aq) to be (1--3) x 10/sup 3/ M atm/sup -1/. The mass accommodation coefficient ..cap alpha.. for uptake of HO/sub 2/ by liquid water is not known and is treated as an adjustable parameter. Results are expressed in terms of yields of HNO/sub 3/(g),H/sub 2/O/sub 2/(aq) relative to the initial photochemical generation rate of OH(g). For large values of ..cap alpha..(> or approx. =10/sup -3/) aqueous-phase H/sub 2/O/sub 2/ formation may be a major radical sink process, but the rate of aqueous-phase H/sub 2/O/sub 2/ production decreases strongly with ..cap alpha..< or approx. =10/sup -3/. Substantial difference, e.g., a factor of as much as 50 in gas-phase HO/sub 2/ concentraiton, is found between kinetic calculations where uptake of HO/sub 2/ by cloud droplets is treated reversibly versus irreversibly. Such differences demonstrate the need to treat the dissolution process as reversible, even for reactive free-radical species.
- Research Organization:
- Environmental Chemistry Division, Brookhaven National Laboratory
- OSTI ID:
- 6139473
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 89:D7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CLOUDS
ATMOSPHERIC CHEMISTRY
WATER CHEMISTRY
CHEMICAL REACTION KINETICS
DISSOLVED GASES
HYDROGEN PEROXIDE
NITRIC OXIDE
SOLUBILITY
CHALCOGENIDES
CHEMISTRY
FLUIDS
GASES
HYDROGEN COMPOUNDS
KINETICS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
REACTION KINETICS
SOLUTES
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)