A new method for calculating activity coefficients of mixed electrolytes

1987 ◽  
Vol 16 (1) ◽  
pp. 11-20 ◽  
Author(s):  
T. K. Lim
Keyword(s):  
Activity Coefficients ◽  
New Method ◽  
Mixed Electrolytes

scholarly journals Method for Estimating Activity Coefficients of Target Components in Poorly Specified Mixtures

2021 ◽  
Author(s):  
Fabian Jirasek ◽  
Jakob Burger ◽  
Hans Hasse
Keyword(s):  
Nmr Spectroscopy ◽  
Activity Coefficient ◽  
Activity Coefficients ◽  
New Method ◽  
Target Component ◽  
Test Cases ◽  
Group Contribution Method ◽  
Bioprocess Engineering ◽  
Separation Processes ◽  
Chemical Groups

Mixtures that contain a known target component but are otherwise poorly specified 15 are important in many fields. Previously, the activity of the target component, which is needed e.g. to design separation processes, could not be predicted in such mixtures. A method was developed to solve this problem. It combines a thermodynamic group contribution method for the activity coefficient with NMR spectroscopy, which is used for estimating the nature and amount of the different chemical groups in the mixture. The knowledge of the component 20 speciation of the mixture is not required. Test cases that are inspired by bioprocess engineering applications show that the new method gives surprisingly good results.

Comparative studies of calculation methods for activity coefficients of unsymmetrical mixed electrolytes

1992 ◽  
Vol 21 (9) ◽  
pp. 963-970 ◽  
Author(s):  
Tiong-Koon Lim ◽  
Siow-Kian Khoo ◽  
F. Hernandez-Luis ◽  
L. Fernandez-Merida ◽  
M. A. Esteso
Keyword(s):  
Activity Coefficients ◽  
Comparative Studies ◽  
Mixed Electrolytes ◽  
Calculation Methods

Ion exchange and solvent extraction equilibria in mixed electrolytes

1969 ◽  
Vol 47 (20) ◽  
pp. 3851-3858 ◽  
Author(s):  
S. K. Patil ◽  
H. D. Sharma
Keyword(s):  
Solvent Extraction ◽  
Ion Exchange ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Activity Coefficients ◽  
Spectroscopic Method ◽  
Distribution Coefficients ◽  
Mixed Electrolytes ◽  
Salting Out ◽  
Extraction Equilibria

The distribution coefficients of 2-thenoyl trifluoroacetone (TTA) between the organic and aqueous phase containing mixtures of ClO4−, NO3−, Cl−, SCN−, and SO42− ions indicate that the activity coefficients of TTA in the aqueous phase are given by ln γ = ΣksiCsi where ksi and Csi are the salting-out parameter and molar concentration of the ith component, respectively. The salting-out effect on TTA follows the usual pattern for a non-electrolyte, i.e. SO42− > Cl− > Br− > ClO4− > SCN− for anions and Li+ > Na+ > H+. In the solvent extraction equilibria, the extraction behavior of the neutral species M(TTA)n may not be similar to that of TTA and thus stability constants determined by this method, wherein there are large changes of anion composition in the aqueous phase to maintain the ionic strength constant, may be in error. The ion exchange equilibria have also been investigated by determining distribution coefficients, D, of metal ions in trace concentrations in mixed electrolyte solutions. The large, poorly hydrated ions are salted into the resin phase in the presence of anions like ClO4− having the property of breaking the water structure. In mixed electrolytes containing perchlorate, nitrate, and chloride ion mixtures, the D values are difficult to rationalize on the basis of the activity coefficients of ions alone. The stability constants for the formation of CaCl+, CaNO3+, BaCl+, and BaNO3+ determined by the ion exchange method at μ = 1 are not in agreement with those obtained by the spectroscopic method.

CALCULATION OF HEATS OF SOLUTION IN SATURATED MIXED ELECTROLYTES

1960 ◽  
Vol 38 (1) ◽  
pp. 161-170
Author(s):  
Y. Iyengar
Keyword(s):  
Temperature Coefficient ◽  
Activity Coefficients ◽  
Solubility Product ◽  
Mixed Electrolytes ◽  
Heats Of Solution ◽  
Harned's Rule

Theoretical equations have been derived for calculating heats of solutions of an electrolyte in its saturated system comprising one or more electrolytes. These expressions involve the application of "Harned's rule" concerning activity coefficients in mixed electrolytic solutions to an extension of van't Hoff's equation dealing with the temperature coefficient of solubility product in non-ideal systems. The commonly occurring case of mixed electrolytic pairs has been considered in detail. Application of theoretical equations to calculate the heats of solutions KCl, NaCl, and KNO3 in the saturated systems KCl–NaCl–H2O and KCl–KNO3–H2O is briefly discussed.

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