The radiolysis of aqueous solutions of Fremyś salt: Rate constants for the reactions with solvated electrons and hydrogen atoms

Abstract

This paper reports the effects of Fremyś salt (the anion NO(SO 3−) 2 is denoted by F) in aqueous solution on the γ radiolytic yield of molecular hydrogen, G H 2 ∗ , and also the kinetics of the competition between F and H 2PO 4 - for the solvated electron yield, Ge aq −, and between F and HCOO- for the hydrogen atom yield, GH. From the results the following rate constants are deduced, corrected for ionic strength effects: k( e aq −+ F) = (1·82 ± 0·5) × 10 9 mol −1 s −1, k(H + F) = 3·0 ± 0·5) × 10 91 mol −1 s −1. The salt effect corrections are discussed in detail and, although the corrected rate constants are shown to be lower than the calculated diffusion controlled rates, the possibility that these reactions are diffusion controlled cannot be definitely excluded. Under conditions of ionic strength ≈ 0·2 mol 1 −1 at pH 6·25–8·5 the values Ge aq − = 2·45 ± 0·1 (corrected for contributions from intraspur processes), GH = 0·57 ± 0·05 and GH = 0·42 are obtained: these values are discussed with reference to other recent work.