Abstract
The reaction between atomic hydrogen and hydroxide ion in aqueous solutions H + OH- - eaq- + H20 has been studied
by pulse radiolysis. The rate constant was measured at pH 11.7 and 12 by following the growth of the hydrated electron
absorption at 600 nm. The activation energy of the reaction has been determined over the temperature range 15-60 "C
as 6.3 f 0.6 kcal/mol(26.4 f 2.5 kJ/mol). From this value and the activation energy of the reverse reaction, the ea; enthalpy
of formation AHf = -32.6 f 1.6 kcal/mol (-136.4 f 6.7 kJ/mol) and its standard entropy So = 16.7 f 5.4 cal/(mol deg)
(69.8 f 22.5 J/(mol deg)) were calculated. The high entropy of solvation A& = 11.7 f 5.4 cal/(mol deg) (49 22.6 J/(mol
deg)) when electrons are transferred from gas phase into aqueous solution indicates that the hydrated electron is a structure
breaker.
Original language | English |
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Journal | Journal of Physical Chemistry |
Volume | 89 |
Issue number | 24 |
Pages (from-to) | 5271-5274 |
ISSN | 0022-3654 |
DOIs | |
Publication status | Published - 1985 |