A SERIES EXPANSION OF THE EXTENDED DEBYE-HUCKEL EQUATION AND APPLICATION TO LINEAR PREDICTION OF STABILITY-CONSTANTS

The Debye-Huckel semiempirical extended equation is frequently used to calculate activity coefficients of chemical species and equilibrium c onstants at ionic strengths different from those used in their experim ental evaluation. A series expansion of the extended Debye-Huckel equa tion is proposed here and checked with experimental data taken from th e literature. The expansion is linear in the ionic parameters and yiel ds a geometrical series which converges rapidly and that enables the a ccurate calculation of interpolated and extrapolated activity coeffici ents and equilibrium constants by simple and multiple linear regressio n without previous knowledge of the ionic parameters.