
%0 Journal Article
%A Sipos, Pal 
%A Hefter, Glenn 
%A May, Peter M. 
%T A Hydrogen Electrode Study of Concentrated Alkaline Aluminate Solutions
%J Australian Journal of Chemistry
%D 1998/06/03
%V 51
%N 6
%P 445-454
%K 
%R https://doi.org/10.1071/C97220
%U https://www.publish.csiro.au/paper/C97220 
%X A detailed study of highly concentrated aqueous alkaline aluminate solutions has been made by hydrogen electrode potentiometry in cells with liquid junction at 25&#176;C in 8 M Na(ClO4) media. Measurements were performed over the total concentration ranges 0&#183;1 M &#60; &#91;NaOH&#93;T &#60; 4&#183;0 M and 0&#183;02 M &#60; &#91;AlIII&#93;T &#60; 3&#183;2 M, and at total concentration ratios of 6&#183;92 &#x2265; &#91;OH-&#93;T/&#91;AlIII&#93;T &#x2265; 4&#183;3. Nernstian electrode behaviour was observed at &#91;NaOH&#93;T &#x2264; c. 2 M in pure NaOH/NaClO4 mixtures. At low &#91;AlIII&#93;T the data were consistent with the formation of only the well known Al(OH)4-(aq) species but there is clear evidence of a systematic release of hydroxide as &#91;AlIII&#93;T and &#91;NaOH&#93;T increase. The data are consistent with the formation of polymeric aluminate complexes having a stoichiometry of Alq(OH)3q - rr+ (q = 4&#8211;7, q + r = 1 or 2). However, unequivocal identification of these species is difficult on account of strong correlations in the data and the possible effects of ion-pairing. 
