ISSN:
1572-8927
Keywords:
Concentrated electrolytes
;
activity coefficients
;
ion-selective electrodes
;
aqueous binary mixtures
;
NaCl−CaCl2 mixtures
;
Harned equation
;
Pitzer formalism
;
excess free energies
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The activity coefficients of NaCl and CaCl2 in NaCl−CaCl2 aqueous mixtures have been measured at 25°C in the ionic strength range I=0.1–20. Where NaCl solubility permitted, both activity coefficients were measured over the whole range of compositions from pure NaCl to pure CaCl2 at constant I. The measurements were made using Na and Ca ion-selective electrodes vs. a Cl ion-selective electrode. The data are fitted to Harned equations of the form $$log \gamma _A = log \gamma _A^0 - \alpha _{AB} y_B - \beta _{AB} y_B^2$$ and were also analyzed using the Pitzer formalism. Excess free energies of mixing are calculated and presented in the I=0.1–5.0 range and the Friedman parameters calculated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00647112
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