Approximate values of the rate constants of radiation reaction of hydrogen atoms and hydroxyl radicals in aqueous solutions

Abstract

1. The radiolysis of aqueous sulfuric acid solutions of ferrosulfate, containing oxygen, was investigated under the action of pulsed electronic radiation. The influence of the addition of NaCl on the value of G(Fe+3) was detected. 2. The mechanism of the radiolytic oxidation of Fe+2 ions at high absorbed dose rates was considered. The decrease in the yield of Fe+3 is due to competition of the reactions of H + OH, Fe2+ + OH and H + O2. 3. Two independent methods of kinetic treatment of the experimental data were used, one of which makes it possible to find the ratio of three reaction rate constants, while the other permits the finding of the ratio of two constants. The absolute values of the reaction rate constants were estimated:\(k_{Fe^{2 + } + OH} = 2.7\cdot10^8 ;k_{H + O_2 } = 5.3\cdot10^9 \) and kH + OH=4.5·1010 liters/mole·sec. 4. The rate constants of a number of radiation reactions of H and OH radicals were estimated on the basis of the values of the relative constants available in the literature and the absolute values obtained.