Temperature dependence of the rate constant for the reaction e –aq+ OH in water up to 150 °C

Abstract

The temperature dependence of the rate constant for the reaction, e^–_aq+ OH → OH^–(1) has been measured in liquid water up to 150 °C. The values of k₁ were derived from fitting the absorbance vs. time plots of the decay of the hydrated electron in pulsed-irradiated deoxygenated 1× 10^–3 mol dm^–3 sodium borate solutions using the computer programme FACSIMILE. The values for k₁ were (2.8 ± 0.2)× 10¹⁰(18 °C), (5.0 ± 0.4)× 10¹⁰(75 °C), (6.0 ± 0.5)× 10¹⁰(100 °C) and (7.2 ± 0.3)× 10¹⁰ dm³ mol^–1 s^–1(150 °C). The temperature dependence of k₁ was found to be much less than for diffusion in water. The temperature dependence of ε_max for the hydrated electron has been determined up to 200 °C.