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The binding mean spherical approximation theory is used to describe the thermodynamic properties of dicarboxylic acid salts by adding a chain term in the free energy. The dianions in these solutions are modeled as flexible charged chains composed of two, three, or four spheres. Five aqueous solutions of such salts are studied in different concentration ranges: dipotassium oxalate, disodium malonate, disodium succinate, potassium tartrate, and sodium tartrate. A description of the experimental deviations from ideality (osmotic and activity coefficients) for these salts is obtained. The model is compared with a previous one that does not include a chain contribution. It is found that the model with a chain contribution provides a more physically sound framework. [ABSTRACT FROM AUTHOR]

It is argued that the Binding Debye–Hückel (BiDH) model proposed by Naseri Boroujeni et al. [J. Chem. Phys. 159, 154503 (2023)] might not be appropriate for the description of Monte Carlo simulation data obtained for primitive model electrolytes. The first reason is that the original Debye–Hückel (DH) theory is of low accuracy for describing deviations from ideality in concentrated solutions of strong salts. The DH framework is thus a poor basis for building a model including association. The second reason is that the mean-spherical approximation, without assumption of association, apparently predicts Monte Carlo (MC) data for primitive electrolytes better than BiDH. Thus, the BiDH model seems to be simply a way of compensating for the deficiencies of DH theory by assuming association. [ABSTRACT FROM AUTHOR]

In this work, the binding mean spherical approximation (BiMSA) theory is used to describe osmotic and activities coefficients for electrolytes solutions up to high temperatures. Four salts are analysed: NaCl, LiCl, $ {\rm MgCl}_2 $ MgCl 2 and $ {\rm CaCl}_2 $ CaCl 2 , in the temperature range of 25 $ ^{\circ } $ ∘ C to 300 $ ^{\circ } $ ∘ C and molalities from 0.05 to 6 molal. A good representation of experimental data is obtained for all salts and temperatures considered by introducing temperature-dependent cation size and permittivity in a suitable way. The proportion of ion pairs (that are formed at sufficiently high temperature in these solutions) for each salt is predicted from the theory, showing a pronounced increase for temperatures above 100 $ ^{\circ } $ ∘ C. A good agreement is found between the values of optimised and experimental association constants given in the literature. [ABSTRACT FROM AUTHOR]

The complete solution to the mean-spherical approximation is given for an arbitrary mixture of ions in a dipolar solvent. The calculation is done for an overall neutral collection of charged hard spheres (ions) and dipoles (solvent) that bear a central point dipole. Previous solutions to this problem were not consistent because they did not include the solvent particles as a (neutral) solute in the mixture. The present solution accounts for this peculiar counterintuitive feature, fully and consistently. Complete expressions for the chemical potentials of the ions and solvent are provided for the first time. To illustrate, a binary 1-1 asymmetric electrolyte solution in a water-like dipolar solvent is considered, and some numerical results are examined. In particular, it is verified that a set of thermodynamic consistency relations are accurately fulfilled. [ABSTRACT FROM AUTHOR]

In the literature, many expressions for the Helmholtz or Gibbs energy of electrolyte solutions have included a term that takes into account the variation of the solution permittivity with the composition of solution (e.g., within the statistical-associated fluid theory formalism). This contribution is often called the "Born" term because it was inspired by the classic expression established by Born to describe the solvation energy of an ion. The present work is an attempt to get more physical insight into this semiempirical "Born" term. The way in which it has been used in the literature is briefly examined, and its typical magnitude is evaluated. Next, it is proposed to use the nonprimitive mean spherical approximation model to calculate the chemical potential of an ion in a solution composed of charged hard spheres (HSs) (the ions) and dipolar HSs (the solvent). The cation and the anion are monovalent monoatomic ions of equal diameter. The dipoles have a different size and mimic water molecules. The theoretical expressions for this model were found to fulfill the Gibbs-Duhem relation, which suggests that they are correct. A rescaled ion-dipole contribution is introduced, in a form that is suitable for inclusion in electrolyte models. It is compared with a "Born" term expressed in the same framework. It is found that the former is in general not well estimated by the latter. The two might even be of opposite signs in the case of ions of sufficiently small size. [ABSTRACT FROM AUTHOR]

The thermodynamic properties of actinide(III) salt solutions at high concentrations and 25 degree Celsius are explored and a new solution of the binding mean spherical approximation (BIMSA) theory is used to reproduce experimental osmotic coefficient variation with concentration for three binary salt solutions. The molecular dynamics (MD) results are used for discussing the parameters used in the BIMSA.

The osmotic second virial coefficients (OSVC's) are calculated analytically for some molecular models in which the solvent is taken into account explicitly. The studies reveal that the solute-solvent interaction has a determinant influence on the observed Osmotic second virial Coefficient (OSVC) value.

The effect of a salt on the kinetics of transfer of acetic acid at a free liquid/liquid boundary was studied using the rotating membrane cell technique. It was found that the quantity of concentrations between 0 and 8 mol L(super -1) is not sufficient for describing the effect of a slat on the kinetics of transfer of acetic acid.

The thermodynamic excess functions of solutions of strong electrolytes and their structure are described by an extension of the mean spherical approximation (MSA). Ionic association is also taken into account by means of Wertheim's formalism(super 18,19) in the MSA(super 20-24). Hydration effects are included using a concentration-dependent cation size and permittivity. The results show a very good representation for a number of mixed salts with a common cation. Cross parameters are introduced for salts without a common cation.

The mean spherical approximation (MSA) model was used to study the osmotic and activity coefficients for aqueous solutions of pure associating electrolytes. The binding MSA was used to examine the association of ions of opposite charges for a variety of solutions of pure salts. Results showed that good fits can be obtained in some solutions of very high concentrations. A description for sulphuric acid was also obtained at low concentration.

The solubility of noble gases and water in molten salts is predicted by developing an analytical parameter-free description in terms of polarizable hard sphere (the gas particle) in a medium composed of charged hard spheres of comparable size (the salt). The chemical potential of solute contains contributions from excluded volume, polarization, and dispersion forces. The polarization of the gas particle is calculated explicitly within the framework of the mean spherical approximation for the ion-dipole mixture. An additional contribution originating from the polarization of the salt is proposed. This effect has been overlooked in previous theoretical studies. Its magnitude is estimated in an approximate way. The description is found to give predictions that are in good agreement with experimental solubility data for noble gases and water in molten KCl and RbCl. The results suggest that volume exclusion and salt polarization may constitute the main two opposing factors affecting this phenomenon. [ABSTRACT FROM AUTHOR]

The thermodynamic properties of highly concentrated aqueous solutions of uranyl nitrate at 25 degree Celsius are described. A new resolution of the binding mean spherical approximation (BIMSA) theory, taking into account 1-1 and also 1-2 complex formation, is developed and used to reproduce, from a simple procedure, experimental uranyl nitrate osmotic coefficient variation with concentration.

The predictive capability of the binding mean spherical appproximation (BIMSA) theory is adopted to describe the thermodynamic properties of electrolytes in the case of aqueous solutions of lanthanide(III) nitrate and chloride salts. Concentrated binary solutions of cerium nitrate are prepared in order to measure experimentally water activity and density as a function of concentration.

Osmotic coefficients of aqueous solutions of lanthanide salts are described using the binding mean spherical approximation (BIMSA) model based on the Western formalism for association. An expression for the osmotic coefficient, derived within the BIMSA, is used to fit data for a wide variety of lanthanide pure salt aqueous solutions at 25 degree Celsius.

A short summary of, the original binding mean spherical approximation (BIMSA) theory and derive analytical equations for the new model of species is presented. These equations are applied to fit the data for a variety of aqueous solutions of acids at 25 degree Celsius.

The self-diffusion coefficients of N(CH3)(sub 4)(super +) ions in a cation-exchange membrane, the Nafion are measured at different time scales. The radiotracer method confirms the NMR results at long time scales that the diffusion does not depend on electrolyte concentration.