Densities and apparent molar volumes of concentrated aqueous LiCl solutions at high temperatures and high pressures

A constant-volume piezometer immersed in a precision liquid thermostat was used to measure the densities of aqueous LiCl solutions from 0.129 to 15.498 mol kg− 1, 291.25 to 607.71 K, and 0.961 to 30.55 MPa. The total uncertainties of density, pressure, temperature, and composition measurements were estimated to be less than 0.06%, 0.05%, 15 mK, and 0.015%, respectively. Apparent molar volumes ϕV were derived using measured values of density for the solutions and for pure water. The apparent molar volumes were extrapolated to zero concentration to yield partial molar volumes at infinite dilution V¯2∞. The temperature, pressure, and concentration dependence of apparent molar volumes were studied. All experimental and derived properties (apparent and partial molar volumes) were compared with experimental values reported in the literature. The maximum apparent and partial molar volumes at temperatures around 315–400 K, depending on concentration and pressure, was determined.