Potentiometric Studies on Sulfato Complex of Aluminium(III) in Aqueous Solution at Elevated Temperatures

Article abstract of DOI:10.1246/bcsj.61.4259

Equilibria in aluminium sulfate solutions with a 1 mol kg^-1 KCl medium and low pH range have been investigated by means of acidity measurements with a hydrogen ion concentration cell from 25 to 125 deg C.The results were treated with a nonlinear least squares computer program to analyze the equilibrium constants for aluminium complexes by using a single parameter type of Debye-Hueckel equation.The log(K/mol^-1 kg) values of the formation constant for the reaction, Al³⁺+SO4^2-->/<-⁺ varied from 3.35 at 25 deg C to 5.34 at 125 deg C and were formulated as a function of temperature.The standard enthalpy and entropy of the complex formation computed from the variation of the formation constant with temperature are presented over the experimental temperature range.The species ^- was not detected under the present conditions.