Kinetics of O�? and O3�? in alkaline aqueous solutions of hydrogen peroxide

Abstract

The photolysis of strong alkaline solutions of H 2 O 2 yields , which in the presence of molecular oxygen forms the ozonide radical ion,. A detailed kinetic study on the reaction mechanisms involved during formation and decay of radical ions in these solutions, in the presence and absence of added scavengers is reported. In order to obtain a complete interpretation of the experimental data, kinetic computer simulations were done using a complete set of reactions. A very good agreement between experimental and computer simulated data is obtained. The following simplified mechanism accounts for the observed first-order decay of in alkaline hydrogen peroxide solutions:with S: scavengers.

Reaction of sulfate and phosphate radicals with α,α,α-trifluorotoluene

“…Flash-photolysis experiments were carried out in a conventional apparatus (Xenon Co. model 720C) with modified optics and electronics. 35 The emission of the flash lamps was filtered with an aqueous saturated solution of TFT in order to minimise TFT photolysis in the reaction system. 18 The pH of the peroxodisulfate solutions is around 2.5 due to the acid content incorporated with the K 2 S 2 O 8 solid batches, containing water and acid (<0.3%) as impurities.…”

Reactions of phosphate radicals with substituted benzenes. A structure–reactivity correlation study

“…Flash-photolysis experiments were carried out in a conventional apparatus (Xenon Co. model 720C) with modiÐed optics and electronics. 5 The emission of the Ñash lamps was Ðltered with aqueous solutions of the substrates at higher concentrations than those used for the experiments, in order to avoid photolysis of the aromatic compounds. The analysis source was a high-pressure mercury lamp (Osram HBO-100 W).…”

Modeling Cl2 formation from aqueous NaCl particles: Evidence for interfacial reactions and importance of Cl2 decomposition in alkaline solution

“…An initial mechanism is developed from the NIST database of solution‐phase chemistry [ Ross et al , 1998] and aqueous‐phase inorganic radical chemistry reviews [ Buxton et al , 1988; Neta et al , 1988]. Significant hydrogen peroxide concentrations are expected in the system, thus aqueous H 2 O 2 photochemistry and thermal/H 2 O 2 ‐initiated ozone decomposition mechanisms, including carbonate ion inhibition effects, were evaluated [ Gonzalez and Martire , 1997; Sehested et al , 1991, 1998; Nemes et al , 2000]. Recently published aqueous chlorine free radical mechanisms are also considered [ Buxton et al , 1998, 2000; Alegre et al , 2000], but aside from Cl 2 hydrolysis, nonradical chlorine chemistry is generally absent from available mechanisms.…”