Radiation chemical data in water using nitrous oxide

By using small doses and very low dose rates, it is shown that in the γ-irradiation of water ~ 8 × 10−5M nitrous oxide completely scavenges eaq− in the absence of other additives and gives a yield G(eaq−) = 2.45 ± 0.1. When used at concentrations of ~ 15 mM, N2O scavenges a second species having a yield G = 0.65 ± 0.1, which can probably be attributed to a hydrated hydrogen atom species resulting from the reaction of eaq– with H3O+ within the spur. Previous studies on the competition between N2O and Haq+ for eaq− have been conducted at concentrations of N2O much too high for simple competition to be valid, which probably accounts for the erratic results obtained. This paper reports on the competition studied at ~ 10−4 M. The results cannot be interpreted either in terms of a simple competition or by one, or both, of the immediate products reacting with either of the additives. The data can only be rationalized by assuming that in acid solution N2O is converted to a species, tentatively suggested to be H2N2O2, which reacts with eaq− 5 times more slowly than does N2Oaq at pH 7.