A quasi-lattice quasi-chemical theory of preferential solvation of ions in mixed solvents

1983 ◽  
Vol 36 (9) ◽  
pp. 1719 ◽  
Author(s):  
Y Marcus
Keyword(s):  
Free Energy ◽  
Dimethyl Sulfoxide ◽  
Gibbs Free Energy ◽  
Preferential Solvation ◽  
Mixed Solvents ◽  
Excess Gibbs Free Energy ◽  
Solvent Mixtures ◽  
Molar Gibbs Free Energy ◽  
Chemical Theory ◽  
Energy Of Transfer

The quasi-lattice quasi-chemical theory is used with a single fitting parameter (Z, the number of nearest neighbours) and data independent of the transfer to solvent mixtures, to describe quantitatively the standard molar Gibbs free energy of transfer of ions from a reference solvent to solvent mixtures, ΔGt� (X, W → S1 + S2), as a function of the composition (mole fraction, x). The independent data include the ΔGt� to the two pure solvents and the excess Gibbs free energy of mixing of these solvents. A defined preferential solvation parameter, g(x), is a convenient measure that is obtained from this treatment. The advantages of employing volume fractions, �, and g(�) rather than mole fractions, x, and g(x), are examined. The theory is applied to the transfer from water of Cl- to ethanol, of Ag+ to acetonitrile or dimethyl sulfoxide, and of NaCl to methanol, and of Na+ from acetonitrile to dimethyl sulfoxide as illustrative examples, comparing the calculated values to experimental data.

Standard thermodynamic transfer functions from water to water + acetone mixtures for a n-nonylcarbon chain attached to different ionic groups

1978 ◽  
Vol 56 (23) ◽  
pp. 2940-2946 ◽  
Author(s):  
Raymond Bury ◽  
Claude Treiner
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Standard Enthalpy ◽  
Transfer Functions ◽  
Mixed Solvents ◽  
Standard Entropy ◽  
Standard Gibbs Free Energy ◽  
Ionic Groups ◽  
Solvent Molecules ◽  
Energy Of Transfer

The standard enthalpy of transfer of trimethyldecylammonium bromide, tetramethylammonium bromide, methyl and decylsodium sulfate have been determined from water to water + acetone mixtures from calorimetric measurements at 298.15 K. The standard entropy function has been calculated using standard Gibbs free energy of transfer data for the same compounds. It is shown that the standard enthalpy and entropy of transfer of a n-nonylhydrocarbon chain attached to the sulfate or to the trimethylammonium groups are quite different whereas the standard Gibbs free energy functions are practically equal in the mixed solvents. It is concluded that the sign of the charge on the ionic groups is responsible for this behaviour and that the influence of this effect extends to a large number of solvent molecules. It is suggested that a similar effect may contribute to the standard enthalpy of so called reference ions: e.g. tetraphenylboron ion casting some doubt on the reliability of these extrathermodynamic approaches at least in mixed solvents, as far as the standard enthalpy function is concerned.

Viscosity of Dimethyl Sulfoxide + 1,4 Dimethylbenzene System

2008 ◽  
Vol 59 (1) ◽  
pp. 45-48
Author(s):  
Oana Ciocirlan ◽  
Olga Iulian
Keyword(s):  
Free Energy ◽  
Dimethyl Sulfoxide ◽  
Atmospheric Pressure ◽  
Entire Range ◽  
Polynomial Equation ◽  
Energy Of Activation ◽  
Excess Gibbs Free Energy ◽  
Experimental Measurements ◽  
Gibbs Energy Of Activation ◽  
Free Energy Of Activation

This paper reports the viscosities measurements for the binary system dimethyl sulfoxide + 1,4-dimethylbenzene over the entire range of mole fraction at 298.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The experimental viscosities were correlated with the equations of Grunberg-Nissan, Katti-Chaudhri, Hind, Soliman and McAllister; the adjustable binary parameters have been obtained. The excess Gibbs energy of activation of viscous flow (G*E) has been calculated from the experimental measurements and the results were fitted to Redlich-Kister polynomial equation. The obtained negative excess Gibbs free energy of activation and negative Grunberg-Nissan interaction parameter are discussed in structural and interactional terms.

Thermodynamic Excess Functions of Binary Liquid Mixtures with Chain Association of One Component*. Part I: The Excess Gibbs Free Energy GE/RT

1976 ◽  
Vol 31 (12) ◽  
pp. 1651-1660 ◽  
Author(s):  
F. Becker ◽  
M. Kiefer ◽  
P. Rhensius ◽  
H. D. Schäfer
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Chain Length ◽  
Liquid Mixtures ◽  
Binary Liquid Mixtures ◽  
Excess Gibbs Free Energy ◽  
Component Part ◽  
Excess Functions ◽  
Binary Liquid ◽  
Self Association

Abstract In this paper equilibrium models for the calculation of the excess Gibbs free energy of binary liquid mixtures are developed, the component A of which undergoes chain-forming self-association whilst the component B acts as an 'inert' solvent. It is shown that the extension of the well-known chain-association model of Mecke and Kempter, in which the probability of chain prolongation is assumed to be independent of chain length, is unable to establish satisfactory results because it does not exhibit sufficient unsymmetry. Reduction of the probability of chain growth with in-creasing chain length leads to an improved model with the geometric series replaced by the exponential series. This model, in which only two parameters are used, i. e. the equilibrium constants K for mutual solvation of A and B, and ρ for self-association of A, allows fitting of isothermal experimental GE /R T literature data on cycloalkanol-cycloalkane, alkanol-alkane, and NMF -CCl4 systems within the limits of experimental error. Compared with the two-parameter Wilson equation which gives equally small standard deviations, our equilibrium model has the advantage of allowing passage from GE to HE data and of being applicable to liquid-liquid equilibria.

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