Measurements of the pressure dependence of the HO/sub 2/ radical self-disproportionation reaction at 298 K

Conference · Thu Jan 30 04:00:00 EST 1986 · J. Phys. Chem.; (United States)

OSTI ID:5897736

Kurylo, M J; Ouellette, P A; Laufer, A H

Flash photolysis kinetic absorption spectroscopy was used to investigate the gas-phase disproportionation reaction of hydroperoxy radicals at 298 K. Measurements of k/sub 1//sigma (where k/sub 1/ is the rate constant and sigma is the HO/sub 2/ absorption cross section) were made as a function of N/sub 2/ and O/sub 2/ pressures between 25 and 600 torr. Our observations of the linear dependence of k/sub 1/ on total pressure as well as of the existence of a finite bimolecular (zero-pressure) reaction component are in good agreement with other recent investigations. An analysis of our data using the equation k/sub 1/ = k/sub 1//sup 0/ + K/sub N/sub 2// (N/sub 2/) + k/sub O/sub 2// (O/sub 2/) yields k/sub 1//sup 0/ = 1.88 x 10/sup 12/ cm/sup 3/ molecule/sup -1/ s/sup -1/, k/sub N/sub 2// = 5.95 x 10/sup -32/ cm/sup 6/ molecule/sup -2/ s/sup -1/, and k/sub O/sub 2// = 4.53 x 10/sup -32/ cm/sup 6/ molecule/sup -2/ s/sup -1/. An error band of +/- 20% is assigned for 95% confidence limits. Together with the earlier studies, the present work provides a detailed data base upon which to make rate constant recommendations for atmospheric modeling. 14 references, 3 figures, 1 table.

• Research Organization: National Bureau of Standards, Gaithersburg, MD
• OSTI ID: 5897736
• Conference Information: Journal Name: J. Phys. Chem.; (United States) Journal Volume: 90:3
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ABSORPTION SPECTROSCOPY
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROPEROXY RADICALS
INFORMATION
KINETICS
MEDIUM TEMPERATURE
MEETINGS
NONMETALS
NUMERICAL DATA
OXIDATION
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PRESSURE DEPENDENCE
RADICALS
REACTION KINETICS
REDUCTION
SPECTROSCOPY