Osmotic coefficient and mean ion activity coefficient of NiCl2 aqueous solution at several temperatures

• Dilution enthalpies of NiCl2 solution were determined at several temperatures.
• A literature review of thermodynamic properties of NiCl2 solution was carried out.
• An expression of Pitzer–Archer activity parameters with temperature was deduced.

The dilution enthalpies of NiCl2 aqueous solution were experimentally determined from nearly saturated to different molalities at T = (298.15, 308.15 and 318.15) K. Combined with evaluated literature data, an expression of Pitzer–Archer activity coefficient parameters with temperature was deduced based on the Pitzer–Archer model and the basic thermodynamic relation among activity coefficient, enthalpy and heat capacity, which was used to calculate the activity and osmotic coefficients of NiCl2 aqueous solution at a certain range of temperature.