Thermodynamic properties of electrolyte solutions. Compressibility studies in aqueous solutions of urayl nitrate

Sound velocities in aqueous solutions of uranyl nitrate were measured at 5 K intervals from T = (283.15 to 323.15) K, within the (0.1 to 2.8) mol · kg−1 concentration range. The sound velocities determined then served to evaluate the isentropic and isothermal compressibilities, the apparent molar compressibilities, the isochoric thermal pressure coefficients, changes of the cubic expansion coefficients with pressure and the heat capacities with volume and these parameters are qualitatively correlated with the changes in the structure of water when uranyl nitrate is dissolved in it.

► Systematic measurements of sound velocities in uranyl nitrate solutions were performed. ► Sound velocities in uranyl nitrate solutions are lower than those in pure water. ► Compressibility properties of these solutions are similar to those of other electrolytes. ► Uranyl nitrate is a structure-making solute and hydration numbers of it are very large.