Osmotic and activity coefficients for binary mixtures of sodium chloride, sodium sulfate, magnesium sulfate, and magnesium chloride in water at 25.deg.. I. Isopiestic measurements on the four systems with common ions

Wu, Yung‐Chi; Rush, Richard M.; Scatchard, George

doi:10.1021/j100858a018

Cited by 129 publications

(74 citation statements)

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“…It is unclear to us why Platford's (1968) parameterization of the Scatchard model (using his isopiestic data for NaCl(aq) + MgCl 2 (aq) mixtures) yields results that are close to the Rard and Miller values for γ NaCl but not those for γ MgCl 2 . Essentially opposite behaviour is observed for the Harned-rule model of Wu et al (1968), which is close to Rard and Miller's (1987) prediction for γ MgCl 2 but not for γ NaCl . Pitzer (1991) has emphasised the importance of solubility data as a means of anchoring isothermal activity and osmotic coefficients to a single well-defined point.…”

Section: (Crosses)mentioning

confidence: 44%

Aqueous electrolyte solution modelling: Some limitations of the Pitzer equations

Rowland

Königsberger

Hefter

et al. 2015

Applied Geochemistry

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Despite intense efforts, general thermodynamic modelling of aqueous electrolyte solutions still presents a difficult challenge, with no obvious method of choice. Even though the Pitzer equations seemingly provide a well-established theoretical framework applicable to many chemical systems over a wide range of temperatures and pressures, they are not as widely adopted as their early promise might have suggested. This is strikingly illustrated by the simultaneous appearance in the literature of numerous, different (and potentially incompatible) Pitzer models alongside a proliferation of alternative theoretical approaches with inferior capabilities.To better understand this problem, the ability of the Pitzer equations to represent the physicochemical properties of aqueous solutions has been systematically investigated for exemplar electrolyte systems. Pitzer ion-interaction parameters have been calculated for selected systems by least-squares regression analysis of published solution data for activity coefficients, osmotic coefficients, relative enthalpies, heat capacities, volumes and densities to high temperatures and pressures. Although satisfactory fits can be achieved when the ranges of conditions are carefully chosen and when sufficient data are available to constrain the regression, the fits obtained tend otherwise to be unsatisfactory. The Pitzer equations do not cope well with gaps and other deficiencies in the regressed data. Profound difficulties, poorly recognized hitherto, can also arise because of variation in the sensitivity of the Pitzer functions to values for different physicochemical properties when these are combined. Given the dimensionality of numerous related thermodynamic properties, all changing as functions of composition, temperature and pressure, these problems are difficult to detect, let alone address, especially in multicomponent systems. The growing practice of improving fits simply by adding basis functions (thereby increasing the number of adjustable parameters) should be deprecated because it increases the likelihood of error propagation, introduces subjectivity, makes independent verification difficult and has deleterious implications for both automated data processing and for consistency between thermodynamic models.

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Section: (Crosses)mentioning

confidence: 44%

Aqueous electrolyte solution modelling: Some limitations of the Pitzer equations

Rowland

Königsberger

Hefter

et al. 2015

Applied Geochemistry

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“…The various approximations used for g n , as a function of the ionic strength, lead to different fitting methods. The methods used in this work have been the usual ones from Scatchard [30,31], Pitzer [4][5][6] and from Lim-HOLL [26,27,[32][33][34]. Below, a summary of this I-dependence is presented:…”

Section: Tablementioning

confidence: 99%

Activity coefficients of NaCl in the NaCl+NaBF4+H2O ternary system at 298.15K

Galleguillos

Graber

Taboada

et al. 2009

Fluid Phase Equilibria

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“…can be written in the form: at the total ionic strengths of the mixtures using the extended ionic interaction model parameters of Table 3, and evaluated the b ij by a least-squares method using our isopiestic results and those of Wu et al [21]. Table 7 summarizes the resulting b ij parameter values.…”

Section: Extended Ion-interaction Model Equations and Calculations Fomentioning

confidence: 99%

“…The data included in the model parameter evaluations are summarized in Table 5. Plotting symbols: , Rard and Miller [39]; , Rard and Miller [30]; , Platford [13]; , Wu et al [21]; , Gibbard and Gossmann [40]; , Padova and Saad [16]; , Stokes [37]; , Robinson and Stokes [36]; , Kuschel and Seidel [17]; ! ", Miladinović, et al [18]; , this study (Table 1); , Frolov et al [38]; , Saad et al [24]; , Robinson and Bower [19].…”

Section: Figmentioning

confidence: 99%

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Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2+(1−y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4⋅MgSO4(aq) at 298.15 K

et al. 2008

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Isopiestic vapor pressure measurements were made for {yMgCl 2 + (1 -y)MgSO 4 }(aq) solutions with MgCl 2 ionic strength fractions of y = (0, 0.1997, 0.3989, 0.5992, 0.8008, and 1) at the temperature 298.15 K, using KCl(aq) as the reference standard.These measurements for the mixtures cover the ionic strength range I = 0.9794 to 9.4318 mol·kg -1 . In addition, isopiestic measurements were made with NaCl(aq) as reference

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Osmotic and activity coefficients for binary mixtures of sodium chloride, sodium sulfate, magnesium sulfate, and magnesium chloride in water at 25.deg.. I. Isopiestic measurements on the four systems with common ions

Cited by 129 publications

References 0 publications

Aqueous electrolyte solution modelling: Some limitations of the Pitzer equations

Aqueous electrolyte solution modelling: Some limitations of the Pitzer equations

Activity coefficients of NaCl in the NaCl+NaBF4+H2O ternary system at 298.15K

Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2+(1−y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4⋅MgSO4(aq) at 298.15 K

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