Temperature dependence of mass accommodation of SO sub 2 and H sub 2 O sub 2 on aqueous surfaces
- Aerodyne Research, Inc., Billerica, MA (USA)
- Boston College, Chestnut Hill, MA (USA)
The authors report the laboratory determination of the temperature-dependent mass accommodation coefficients of SO{sub 2} and H{sub 2}O{sub 2} on aqueous surfaces over the range 260-292 K. Mass accommodation kinetics involve fundamental chemical interactions of liquid surfaces about which little is known. Uptake of SO{sub 2} and H{sub 2}O{sub 2} by cloud droplets is believed to be critical to S(IV) oxidation in the troposphere. Our experimental method combines a monodisperse train of droplets (200 {mu}m in diameter) and a low-pressure flow reactor. Uptake rates of trace gases are determined by measuring changes in trace gas number density as a function of exposed liquid surface area. Experiments with systematic variation of water vapor and rare gas partial pressures permit deconvolution of gas diffusion and temperature-dependent mass accommodation. In the case of SO{sub 2}, variation of droplet-gas interactions on millisecond time scales resolved pH-dependent saturation effects at the aqueous surface. Results for SO{sub 2} show {gamma}{sub 273} = 0.11 {plus minus} 0.02 with no significant temperature variation. H{sub 2}O{sub 2} shows a strong temperature dependence consistent with an attractive well depth of at least 26 kJ mol{sup {minus}1} with {gamma}{sub 273} = 0.18 {plus minus} 0.02. These results are discussed in terms of the different aqueous solubilities of SO{sub 2} and H{sub 2}O{sub 2}.
- OSTI ID:
- 5032830
- Journal Information:
- Journal of Physical Chemistry; (USA), Vol. 93:3; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HYDROGEN PEROXIDE
MASS TRANSFER
SULFUR OXIDES
AQUEOUS SOLUTIONS
CLOUDS
DROPLETS
EXPERIMENTAL DATA
MEDIUM TEMPERATURE
RAIN
SURFACE PROPERTIES
TIME DEPENDENCE
WATER VAPOR
ATMOSPHERIC PRECIPITATIONS
CHALCOGENIDES
DATA
DISPERSIONS
FLUIDS
GASES
HYDROGEN COMPOUNDS
INFORMATION
MIXTURES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PARTICLES
PEROXIDES
SOLUTIONS
SULFUR COMPOUNDS
VAPORS
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