The hydrolysis of metal ions. Part 11. The ionic strength dependence of gallium(III)

Abstract

An automated potentiometric titration technique has been used to study the behaviour of the gallium(III) ion in 0.10, 0.50, 1.0, and 1.5 mol dm^–3 potassium nitrate at 25 °C. Data analysis indicates the presence of the monomeric species [Ga(OH)]²⁺ and [Ga(OH)₂]⁺. The –log β_pq values for these species are estimated to be 3.16 (0.02) and 7.07 (0.02), respectively, in 0.10 mol dm^–3 KNO₃, 3.73 (0.03) and 7.15 (0.02) in 0.50 mol dm^–3 KNO₃, 3.92 (0.02) and 7.79 (0.03) in 1.0 mol dm^–3 KNO₃, and 4.02 (0.03) and 7.73 (0.03) in 1.5 mol dm^–3 KNO₃(the standard deviations have been given in parentheses). The dependence of the two formation constants on ionic strength has been determined.