Pulse radiolysis study of aqueous nitric acid solutions. Formation mechanism, yield, and reactivity of NO sub 3 radical. [Pulsed electron beams]

Journal Article · Thu May 30 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100164a050· OSTI ID:5952453

Katsumura, Y; Jiang, P Y; Nagaishi, R; Oishi, T; Ishigure, K ^[1]; Yoshida, Y ^[2]

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1. Univ. of Tokyo (Japan)
2. Univ. of Tokyo, Ibaraki (Japan)

A pulse radiolysis study of aqueous nitric acid and nitrate solutions has been carried out. The formation kinetics of NO{sub 3} radical was followed with nanosecond time resolution. Two formation processes of NO{sub 3} in nitric acid solutions were directly demonstrated: a fast one completed during the electron pulse and a slow one occurring in a microsecond time range. In nitrate solutions, only the fast formation process was observed. The slow formation process in nitric acid solutions was confirmed to be the reaction of OH radicals with undissociated nitric acid molecules, OH + HNO{sub 3} {yields} H{sub 2}O + NO{sub 3}, with a rate constant of (1.4 {plus minus} 0.1) {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}. The fast formation process is most probably the direct action of radiation on nitrate anion or nitric acid: NO{sub 3}{sup {minus}} (gamma radiation) {yields} e{sup {minus}} + NO{sub 3} or HNO{sub 3} (gamma radiation) {yields} HNO{sub 3}{sup +} + e{sup {minus}} {yields} NO{sub 3} + H{sup +} + e{sup {minus}}. The molar absorption coefficient of NO{sub 3} was evaluated as 1,300 {plus minus} 100 M{sup {minus}1} cm{sup {minus}1} at 640 nm. On the basis of this result, G values of NO{sub 3} were evaluated in nitric acid, lithium nitrate, and sodium nitrate solutions. The main decay reaction of NO{sub 3} was proposed to be NO{sub 3} + NO{sub 2} {yields} N{sub 2}O{sub 5} in nitric acid solutions and its rate constant was evaluated as (1.7 {plus minus} 0.3) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}. Rate constants of reactions of NO{sub 3} with radiolytic products and some other compounds were obtained.

• OSTI ID: 5952453
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:11; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400600* -- Radiation Chemistry
ABSORPTION SPECTROSCOPY
AQUEOUS SOLUTIONS
BEAMS
CHALCOGENIDES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
DISPERSIONS
ELECTRON BEAMS
EXPERIMENTAL DATA
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
KINETICS
LEPTON BEAMS
MIXTURES
NITRIC ACID
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
RADICALS
RADIOLYSIS
REACTION KINETICS
RESOLUTION
SOLUTIONS
SPECTRA
SPECTROSCOPY
TIME DEPENDENCE
TIME RESOLUTION
TIMING PROPERTIES
VISIBLE SPECTRA