scholarly journals Nonlinear Contribution of Hydrophobic Hydration in Osmotic Coefficients of Electrolyte Solutions

2015 ◽  
Vol 72 ◽  
pp. 73-78 ◽  
Author(s):  
V.V. Sergievskii ◽  
A.M. Rudakov ◽  
E.A. Ananyeva ◽  
M.A. Glagoleva
Keyword(s):  
Osmotic Coefficients ◽  
Hydrophobic Hydration ◽  
Electrolyte Solutions ◽  
Nonlinear Contribution

Thermodynamics of electrolyte solutions: activity coefficients of NaCl in the NaCl–NiCl2–H2O system at 25, 35, and 45 °C

1990 ◽  
Vol 68 (2) ◽  
pp. 294-297 ◽  
Author(s):  
Ch. Venkateswarlu ◽  
J. Ananthaswamy
Keyword(s):  
Activity Coefficients ◽  
Silver Chloride ◽  
Osmotic Coefficients ◽  
Reference Electrode ◽  
Nickel Chloride ◽  
Electrolyte Solutions ◽  
Pitzer Formalism ◽  
Harned Coefficients ◽  
Silver Silver ◽  
Silver Silver Chloride

The activity coefficients of NaCl in the NaCl–NiCl2–H2O system were estimated at 25, 35, and 45 °C and total ionic strengths of 0.5, 1.0, 2.0, and 3.0 m by an EMF method using a Na-ion selective electrode and a silver–silver chloride reference electrode. The Harned coefficients were calculated at all the temperatures studied. At 25 °C the data were analysed using the Pitzer formalism. The osmotic coefficients and the excess free energies of mixing were also calculated at 25 °C. Keywords: activity coefficients, sodium chloride, nickel chloride, Pitzer equations, thermodynamics.

Application of a Chemical Thermodynamic Model to the Gibbs Free Energy of Aqueous Electrolyte Solutions. New Equations for the Activity and Osmotic Coefficients

1991 ◽  
Vol 44 (9) ◽  
pp. 1195
Author(s):  
JV Leyendekkers
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Short Range ◽  
Van Der Waals ◽  
Osmotic Coefficients ◽  
Electrolyte Solutions ◽  
Solute Concentration ◽  
Volume Effect ◽  
Chemical Thermodynamic ◽  
Short Range Repulsion

The chemical thermodynamic (CT) model, based on the extended Tait equation, has been applied to the Gibbs free energy of aqueous solutions of sodium chloride and potassium chloride at 25°C. Equations for the activity and osmotic coefficients were derived. These are made up of the Debye-Huckel limiting slope term, a van der Waals co-volume effect term covering short-range repulsion, a term covering the water compression by the solute and a short-range attractive term. The distance of closest approach derived from the model is the same as that expected for the van der Waals effect. The individual components of the partial molal free energy, that is, the effects of solute concentration on the water and solute respectively, have been calculated.

A simple perturbation method for electrolyte solutions

1989 ◽  
Vol 54 (11) ◽  
pp. 2872-2878
Author(s):  
Jan Sýs ◽  
Anatol Malijevský ◽  
Stanislav Labík
Keyword(s):  
Helmholtz Free Energy ◽  
Osmotic Coefficients ◽  
Perturbation Expansion ◽  
Electrolyte Solutions ◽  
Simple Expression ◽  
Monte Carlo Data ◽  
First Order ◽  
Restricted Primitive Model ◽  
Heats Of Dilution ◽  
Perturbation Potential

The first order perturbation expansion of the Helmholtz free energy was used to calculate the thermodynamic properties of aqueous electrolytes. The restricted primitive model was used as the reference system. Its properties were determined using semiempirical formulae consistent with simulated Monte Carlo data. A simple expression with two adjustable parameters was chosen for the perturbation potential. Integral heats of dilution and osmotic coefficients of alkaline halides and tetraalkylamonium bromides were calculated. An excellent agreement with the tabulated data was found up to the concentrations of 2-3mol/dm3.

Procedures for Calculating the Osmotic Coefficient of Artificial Sea Waters

1973 ◽  
Vol 53 (3) ◽  
pp. 685-693 ◽  
Author(s):  
M. Whitfield
Keyword(s):  
Curve Fitting ◽  
Osmotic Coefficient ◽  
Sea Water ◽  
Osmotic Coefficients ◽  
Electrolyte Solutions ◽  
Solution Composition ◽  
Estuarine Waters ◽  
Temperature Range ◽  
Wide Pressure

Recent equations for calculating the osmotic coefficient of sea water from the properties of the component single-electrolyte solutions are discussed. Two equations are introduced that together provide accurate predictions of the osmotic coefficient of sea water for ionic strengths up to 4 M (equivalent to a fivefold concentration of standard sea water). Since they take into account the detailed solution composition these equations should be useful for calculating the osmotic coefficients of estuarine waters and of biological salines where procedures based on curve fitting to standard sea-water data may be inapplicable. Extensions of the calculations to cover a wide pressure and temperature range are discussed in some detail.

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