Guggenheim, Davis

Bronsted-Guggenheim-Scatchard specific ion interaction theory (SIT) (cf. Grenthe and Wanner 1989 Giridhar and Langmuir 1991 Nordstrom and Munoz 1994) is an ion- and electrolyte-specific approach to activity coefficients, which is, therefore, theoretically capable of greater accuracy than the Davies equation. The general SIT equation for a single ion, i, can be written... 

If one ignores the second term in Equation 1.28, one obtains the truncated Guggenheim equation (Equation 1.29), which is identical to the Davies equation, but with [Ir equal to unity. The reader should be aware that many authors refer to Equation 1.29 as the Guggenheim equation. 

In this section, applications of the Davies and truncated Guggenheim equations are demonstrated through worked examples from the literature. 

Data compilation, pKa values and, 26-28 Davies modification, 21-22 Debye-Htickel equation, 8,11 Davies modification of, 21-22 Guggenheim modification of, 10, 21 Dielectric constant (s), 20... 

An Inconvenient Truth Produced by Lawrence Bender, Scott A. Bums, and Laurie David directed by Davis Guggenheim edited by Jay Lash Cassidy and Dan Swiedik. 

Davies equation - a suggested equation for the Guggenheim parameter... 

Figures 4.3 and 4.4 show the mean activity coefficients of NaCl at 25°C calculated with the equations of GUntelberg, Guggenheim and Davies plotted against Robinson and Stokes (5) data. The results for a 1-2 electrolyte, K SO, are shown in Figure 4.5. The experimental data is smoothed data from Goldberg (13).

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