Physicochemical Properties of the Gallium(III) Chloride–Hydrochloric Acid–Water System

The physicochemical properties of the gallium(III) chloride–hydrochloric acid–water system were studied in a wide range of concentrations from 1.0 to 75.0 wt % at 25°C. The relevance of this study is due to the accumulation of significant quantities of gallium chloride solutions in the form of intermediate products formed in various fields of science and technology, as well as the lack of information about their properties in the literature. The density, electrical conductivity, viscosity, and ultrasound velocity were measured using standard instruments. The apparent molar volumes, adiabatic compressibility coefficients, and the degree of hydrolysis were calculated based on the experimental data. According to the obtained data, it was found that the presence of hydrochloric acid leads to an increase in the apparent molar volume of GaCl3 and a decrease in the viscosity and electrical conductivity of the system due to the formation of chlorogallic acid complexes. The obtained data on changes in the physicochemical quantities are of great practical importance and can be used to optimize the processes of isolating gallium trichloride from solutions and to enrich the field of knowledge about gallium chemistry.