"PREDICTION OF ACTIVITY COEFFICIENTS, NONLINEAR REGRESSION. For an electrolyte, the mean activity coefficient f± is a measure of ionic interactions and of departure from ideal conditions. The modified Debeye-Hückel (DH) limiting law can be used to predict the mean activity coefficient. A' is constant that depends on solvent and temperature. I is the total ionic strength.Zplus and Zminus are the charges of the cation and anion, respectively. *** Answer(s) to Problem(s) **** (c) Copyright P CSCC, Inc., 1993Equations are data are already entered into program. Type S to start fit. Use default tolerance, type (enter). Only independent variables followed by the '=' sign are optimized. A' equals 1.06 in modified DH equation. Type any key to exit. ||Determine the equation that gives the best description of the activity coefficient data for sodium chloride over the concentration range from 0.001-0.1 mol/dm3. Data in (concentration,ln f±) pairs are (1e-3, -0.0357), (5e-3, -0.0753), (1e-2, -0.1027), (5e-2, -0.1978) and (0.10, -0.2468). (from Norris, A. C., op. cit.) Type comma key to see entire comment. Type (F2) to return to application file."
