
%0 Journal Article
%A Richmond, TG 
%A Johnson, JR 
%A Edwards, JO 
%A Rieger, PH 
%T Kinetics of pyroarsenate hydrolysis in aqueous solution
%J Australian Journal of Chemistry
%D 1977/06/01
%V 30
%N 6
%P 1187-1194
%K 
%R https://doi.org/10.1071/CH9771187
%U https://www.publish.csiro.au/paper/CH9771187 
%X The rate of hydrolysis of pyroarsenate in 0.1 mol dm-3 NaClO4 solutions, pH 6-9, was measured by a pH-stat technique at temperatures ranging from 278 to 298 K. The pKa of HAs2O73-, found to be the predominant reactant under these conditions, was 7.3 and 7.6 at 283 and 298 K, respectively. The hydrolysis rate constant for HAs2O73- was 0.05 s-1 at 298 K with activation parameters &#916;H? = 49 ± 9 kJ mol-1 and &#916;S? = -107 ± 30 J mol-1 K-1. An associative mechanism is indicated. 
