The activity and osmotic coefficients of aqueous calcium chloride at 298.15 K

Abstract

A critical evaluation of the mean activity, γ., and osmotic coefficients, γ±, and osmotic coefficients, ∮, of aqueous calcium chloride at 298.15 K is presented for the concentration range of 0 to 10 mol⋅kg−1. Osmotic coefficients were calculated from direct vapor pressure measurements, from isopiestic measurements or from freezing point depression measurements. Activity coefficients were calculated from electro-motive force measurements of galvanic cells, both without liquid-junction and with transference, and from diffusion data. A non-linear least-squares program was used to fit data from all sources using both ∮ and in γ± as a function of molality. An eight-parameter extended Debye-Huckel equation describes the osmotic coefficient, the mean activity coefficient, and the excess free energy as a function of molality. The scientific literature has been covered through July 1976.