Kinetic study of HONO formation and decay reactions in gaseous mixtures of HONO, NO, NO/sub 2/, H/sub 2/O, and N/sub 2/

Journal Article · Thu Jul 01 04:00:00 EDT 1976 · Environ. Sci. Technol.; (United States)

DOI:https://doi.org/10.1021/es60118a007· OSTI ID:7338365

Chan, W H; Nordstrom, R J; Calvert, J G; Shaw, J H

A kinetic study of the nitrous acid decay reaction, 2HONO yields NO + NO/sub 2/ + H/sub 2/O(2), and the formation reaction, NO + NO/sub 2/ + H/sub 2/O yields 2HONO (1), is made using essentially continuous FT-IR monitoring of the reactants and products in mixtures at the ppM level. The data suggest that the reactions are homogeneous for the conditions employed in this study. The results give: k/sub 1/ = (2.2 +- 0.7) x 10/sup -9/ ppM/sup -2/ min/sup -1/ and k/sub 2/ = (1.4 +- 0.4) x 10/sup -3/ ppM/sup -1/ min/sup -1/ at 23/sup 0/C. The homogeneous generation of HONO may be important in power plant plumes and in auto exhaust gases during the early stages of the dilution of these NO/sub x/-H/sub 2/O-rich mixtures. Reactions 1 and 2 are a negligible source and sink of HONO in the atmosphere once the usual low ambient levels of NO and NO/sub 2/ are achieved. These reactions may influence smog formation in urban atmospheres during the early morning hours when nitrous acid formation by aternative pathways is slow. For these conditions the sunlight photolysis of HONO may be the major source of HO-radicals which, in combination with hydrocarbons and their oxidation products, lead to NO yields NO/sub 2/ conversion, O/sub 3/ development, and other manifestations of photochemical smog.

• Research Organization: Ohio State Univ., Columbus
• OSTI ID: 7338365
• Journal Information: Environ. Sci. Technol.; (United States), Journal Name: Environ. Sci. Technol.; (United States) Vol. 10:7; ISSN ESTHA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AUTOMOBILES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
DECOMPOSITION
EARTH ATMOSPHERE
ELEMENTS
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXYL RADICALS
INORGANIC ACIDS
KINETICS
NITRIC OXIDE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NITROUS ACID
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OZONE
PHOTOCHEMICAL OXIDANTS
PLUMES
POLLUTION
POWER PLANTS
QUANTITY RATIO
RADICALS
REACTION KINETICS
SMOG
SYNTHESIS
URBAN AREAS
VARIATIONS
VEHICLES
WASTES