In 1978, Kusik and Meissner (1978) presented an equation for the prediction of activity coefficients in aqueous electrolyte solutions, based on parameter q. In this work the temperature dependency of the Kusik-Meissner parameter, q, was studied.
Although the activity coefficients of electrolytes are readily available in binary and ternary solutions at 298.15K, little or no data are available a t other temperatures. The calculation of properties such as activities, vapor pressures, solubilities, and those corresponding to strong electrolytes, currently found in leaching, precipitation, crystalization, evaporation processes and others, generally have been handicapped by this lack of data. There are several equations for predicting these activity coefficients (Kusik and Meissner, 1978; Bromley, 1973; and Pitzer, 1973) but unfortunately, little or no parameter values are available a t temperatures other than 298.15K. In industrial practice it is common to find a wide range of temperature for which no correlation is available.
Kusik and Meissner presented the following equation: also be expressed as:
Note that the first term of Eq. 2 has the form of Debye-Huckel's model.
Kusik and Meissner suggested the following equation for q at temperatures other than 298.15K (applicable for any ionic strength):