Product quantum yields for the 305-nm photodecomposition of NO/sub 3//sup -/ in aqueous solution

Journal Article · Thu Nov 03 04:00:00 EST 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100333a022· OSTI ID:6083408

Warneck, P; Wurzinger, C

The radical scavenging technique with product analysis was employed to determine quantum yields for the two main processes (1) NO/sub 3//sup -/ + hv = NO/sub 2//sup -/ + O and (2) NO/sub 3//sup -/ + H/sup +/ hv = NO/sub 2/ + OH in dilute, air-saturated solutions of sodium nitrate. Oxygen atoms were detected by their reaction with cyclopentene and the production of ethene. The quantum yield found was /phi/(O) = (1.1 /plus minus/ 0.1) x 10/sup -3/. The generation of OH radicals was confirmed by their reactions with benzene to give phenol and with 2-propanol to produce acetone. The second reaction was used to establish an OH quantum yield of /phi/(OH) = (9.2 /plus minus/ 0.4) x 10/sup -3/. Nitrite was formed with a similar yield in the pH region 5-12, whereas at lower pH the yield declined. Formate as a scavenger converts OH radicals toward O/sub 2//sup -//HO/sub 2/ radicals which produce H/sub 2/O/sub 2/. The yield of H/sub 2/O/sub 2/ at pH 5.6 was lower than expected whereas that of NO/sub 2//sup -/ was higher. Reactions are postulated to explain this observation as well as the pH dependence of nitrite formation.

• Research Organization: Max-Planck-Institut fuer Chemie, Mainz (West Germany)
• OSTI ID: 6083408
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:22; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ALKENES
ANIONS
AQUEOUS SOLUTIONS
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DATA
DECOMPOSITION
DISPERSIONS
EFFICIENCY
ETHYLENE
EXPERIMENTAL DATA
HYDROCARBONS
HYDROXYL RADICALS
INFORMATION
IONS
KINETICS
MIXTURES
NITRATES
NITROGEN COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PH VALUE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
REACTION KINETICS
SOLUTIONS
YIELDS