Speciation of Al3+in fairly concentrated solutions (20–200 mmol L−1) at I=1 mol L−1(NaNO3), in the acidic pH range, at different temperatures

AbstractThe hydrolysis of Al3+was studied in aqueous 1 mol L−1NaNO3solution at different concentrations (20–200 mmol L−1) and temperatures (283.15–343.15 K) by potentiometry (ISE-H+,glass electrode). Many different speciation models were considered in the calculations and it was found that the best model is represented by the following species: Al(OH)2+, Al(OH)45+, Al13(OH)327+. Hydrolysis constants and enthalpy changes at different temperatures are reported.