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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 19 (1970), S. 38-44 
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Polarisierbarkeit des Wasserstoffmoleküls wurde für einen Bereich von Kernabständen mit Hilfe der gekoppelten als auch der entkoppelten Hartree-Fock-Störungstheorie mit einer Basis von Gauss-Funktionen berechnet. Es wird gezeigt, daß eine relativ einfache Funktion mit der geeigneten Beimischung von s- und p-Charakter Polarisierbarkeiten ergibt, deren Genauigkeit solchen aus Rechnungen mit sehr komplizierten Wellenfunktionen vergleichbar ist.
    Abstract: Résumé Calcul de la polarisabilité de l'hydrogène moléculaire pour un éventail de distances internucléaires par la théorie des perturbations Hartree-Fock, couplée et non couplée, dans une base de fonctions gaussiennes. Une fonction relativement simple présentant un mélange convenable de caractère s et p fournit des polarisabilités, comparables au point de vue précision avec celles obtenues à partir de fonctions d'ondes très élaborées.
    Notes: Abstract The polarizability of molecular hydrogen has been calculated over a range of internuclear separations by Hartree-Fock perturbation theory, both coupled and uncoupled, using Gaussian functions as basis set. It is shown that a relatively simple function having the proper admixture of s and p character can yield polarizabilities comparable in accuracy with those obtained from highly sophisticated wave-functions.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 16 (1987), S. 917-926 
    ISSN: 1572-8927
    Keywords: Activity coefficients ; binary mixed electrolytes ; HCl ; KCl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two new methods are reported from which the mixing activity coefficients of both electrolytes in a binary mixture can be computed simultaneously from fitting the activity coefficients of one of the electrolytes only and without using the derivatives of the parameters. Furthermore, variations caused by changing the fractional ionic strengths at fixed total ionic strength entails no assumptions about the ionic strength dependence of the mixing coefficients. The methods are shown to be superior to other methods. The results for the system HCl+KCl at 25°C are discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 8 (1979), S. 277-282 
    ISSN: 1572-8927
    Keywords: Activity coefficients ; hydrobromic acid ; barium bromide ; mixed electrolytes ; Pitzer's equations ; Scatchard's equations ; ionic interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electromotive-force measurements are reported for mixtures of HBr and BaBr2 in water at 25°C at constant total ionic strengths. Activity coefficients for HBr were analyzed using Pitzer's equations and Scatchard's neutral-electrolyte treatment. Both methods gave comparable results if the effects of higher-order electrostatic terms on the H+−Ba+2 interactions were included in Pitzer's treatment. Furthermore, the value of the H+−Ba+2 interaction parameter, θ(s), which should be independent of the anion, is indeed close to that for binary mixtures of these ions having chloride as common ion.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 9 (1980), S. 785-789 
    ISSN: 1572-8927
    Keywords: Mean ionic activity coefficients ; e.m.f. ; HBr ; SrBr2 ; H2O ; ionic interactions ; Pitzer equations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Mean ionic activity coefficients at 25°C for HBr and SrBr2 in the system HBr + SrBr2 + H2O at constant total ionic strengths of 0.1–2 mol-kg−1 have been obtained by e.m.f. measurements. The results support previous findings1,2) that Pitzer's treatment of asymmetric mixtures of this type allowing for higher order electrostatic interactions between ions of the same charge sign is precise. For the HX+NX2+H2O systems the Pitzer interaction parameter ΨHNX can be conveniently set to zero without loss in accuracy in the description of the experimental results. With the exception of Mn2+, values of θHN (s), the Pitzer parameter governing short-range interactions between H+ and N2+ ions, vary only slightly with the Pauling ionic crystal radii of the different cations (N=Mg, Ca, Sr, Ba, Ni and Co).
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 9 (1980), S. 507-515 
    ISSN: 1572-8927
    Keywords: Activity coefficient ; total molal quantities ; mixed electrolytes ; ionic interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Activity coefficients in binary mixed electrolytes are expressed in terms of the parameters from total molal quantities. Two versions of the calculations are presented and compared with the methods of Pitzer and Scatchard. For each method interrelations among the various parameters are examined. The system being tested is HCl+CoCl2+H2O at 25°C, for which new experimental data at low ionic strengths are included.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1572-8927
    Keywords: Activity coefficients ; mixed electrolytes ; Scatchard ; Pitzer and Lim's methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Several methods for the calculation of activity coefficients for binary mixed electrolytes are compared. Their accuracies are analysed and the reasons for the different degrees of accuracies are given.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 7 (1978), S. 291 
    ISSN: 1572-8927
    Keywords: Activity coefficiet ; mixed electrolytes ; Scatchard's equations ; Pitzer's equations ; higher-order electrostatic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Activity coefficients for CHl in the system HCl+NiCl 2 +H 2 O at 298.15°K at constant total ionic strengths of 0.1, 0.5, 1.0, 2.0, and 3.0 moles-kg −1 have been determined by an emf method. A comparison was made between Scatchard's and Pitzer's interpretations of mixed-electrolyte solutions for this system and six related systems. Preference can be given to Pitzer's method provided cognizance is taken of the effects of higher-order electrostatic terms beyond the Debye-Hückel approximation on the thermodynamic properties of asymmetrical mixtures.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 10 (1981), S. 683-691 
    ISSN: 1572-8927
    Keywords: Activity coefficients ; hydrochloric acid ; lanthanum chloride ; ternary mixtures ; Harned's rule ; Pitzer's equations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Activity coefficients of hydrochloric acid in aqueous solutions of lanthanum chloride were determined by an emf method at 25°C over an ionic strength range 0.05–3 mol-kg−1. Harned's rule was obeyed within experimental error by the acid in all the mixtures. However, the fit with Pitzer's equations was not as good as the Harned rule fit, even though the effects of higher-order electrostatic terms were considered. Activity coefficients for the salt in the mixtures were derived using the Pitzer equations and fitted to the Harned equation, whereupon Harned's rule was found to be valid for the salt up to an ionic strength of 0.3 mol-kg−1 only.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 21 (1992), S. 121-128 
    ISSN: 1572-8927
    Keywords: HOLL ; Pitzer's and Scatchard's methods ; NaBr ; CoCl2 ; NaFormate ; HCl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract As an extension of the All Mixing Coefficients method which was developed in 1987, we have now incorporated the Higher Order Limiting Law into the method so that it satisfies the HOLL while it retains its high accuracy and other important features. One mixture each symmetrical and unsymmetrical were used for testing. The calculated results are analysed and compared with other well known methods. The superiority of the present method is shown.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 7 (1978), S. 349-355 
    ISSN: 1572-8927
    Keywords: Mixed electrolytes ; mixed solvents ; Harned's method ; ion-ion interactions ; ion-solvent interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electromotive-force measurements of the cell Pt, H2(g, 1 atm)|HCl(m1), NH4Cl(m2), methanol(X%), Water(100−X)%|AgCl|Ag have been made at 25°C for m1+m2=1 mole-kg−1 and X=0, 10, 20, 30, 40, and 50% methanol by weight. Hydrochloric acid obeys Harned's rule in aqueous solutions, but a quadratic term is required in the mixed solvents. The Harned coefficients for the acid vary with solvent composition, and this invalidates the applicability of Harned's method for estimating activity coefficients for single electrolytes in mixed solvents. This method is described and the reason for the inapplicability of the method is discussed in terms of ion-ion and ion-solvent interactions.
    Type of Medium: Electronic Resource
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