The model proposed by Chen et al. for treating nonideality in concentrated electrolyte solutions has been extended to the correlation of the densities of solutions of single electrolytes (1: 1, 2: 1, 1:2, and 2:2) in terms of Chen's energy interaction parameters rca,,, and T , , ,~~. At any single temperature, only three adjustable parameters, v;(the partial molar volume of the solute at infinite dilution), and the pressure derivatives (dTca,ffl/dp)r and (dTffl,ca/dp), are required for correlating the density as effectively as the conventional treatment employing a power series in (molality)"2. For some electrolytes, only the latter two parameters are required, as tabulated values also lead to satisfactory correlations.The treatment can be extended to cover the temperature range 0-100°C, using either r,,,,, and T , , ,~~ values derived from activity or osmotic coefficients, or constant rca,,, and T , , ,~~ values, but the irregular variation with temperature of the pressure derivatives precludes their representation by simple analytical functions, and individual values of the pressure derivatives at each temperature are necessary.
