The solubility of thallium(III) hydroxide in 0.01 M sodium perchlorate solu
tions is studied experimentally. At pH 6.31-8.42, the solubility is indepen
dent of the solution acidity and averages 0.8 mu mol/l. In the range of the
specified pH values, almost all thallium(III) exists as electroneutral hyd
roxo complexes Tl(OH)(3)(0).