Thermodynamics of Aqueous Reciprocal Salt Systems. III. Isopiestic Determination of Osmotic and Activity Coefficients of Aqueous MgCl2, MgBr2, KCl and KBr at 100.3 degrees C.

Aqueous solutions of the alkaline-earth metal chlorides at elevated temperatures. Isopiestic molalities and thermodynamic properties

“…The isopiestic results of Fangha¨nel and Grjotheim (33) for MgCl 2 (aq) agree quite well with our measurements after recalculation of their results {to conform to our CaCl 2 (aq) model (1) } which was necessary because they used the model of Ananthaswamy and Atkinson (79) for CaCl 2 (aq) as an isopiestic standard. In the case of SrCl 2 (aq), there are no excess Gibbs free energy results at temperatures between our isopiestic measurements and T = 298.15 K except the cell potential results of Longhi et al, (56) which are for quite low molalities.…”

Isopiestic investigation of the osmotic coefficients of MgBr2(aq) and study of bromide salts solubility in the (m1KBr+m2MgBr2)(aq) system at T=323.15K. Thermodynamic model of solution behaviour and (solid+liquid) equilibria in the MgBr2(aq), and (m1KBr+m2MgBr2)(aq) systems to high concentration and temperature

“…In this study, we develop the model for mixed system (m 1 KBr + m 2 MgBr 2 )(aq) using the KBr(aq) parameterization from reference [19] and without any adjustments of the values of the ion-interaction parameters and chemical potential of potassium bromide solid. Several authors (at T = 298.15 K: [45][46][47]21]; at T = 373.45 K: [48]) have constructed solution models for Mg-Br interactions. Only the T = 298.…”

An isopiestic study of aqueous NaBr and KBr at 50°C: Chemical equilibrium model of solution behavior and solubility in the NaBr–H2O, KBr–H2O and Na–K–Br–H2O systems to high concentration and temperature

“…In their comprehensive isopiestic study Holmes and Mesmer (1998) determined the osmotic coefficients of NaBr(aq) and KBr(aq) at saturation pressure from 110 to 225°C and up to %6.2 m NaBr and %7.4 m KBr. In intermediate temperature range (from 25 to 110°C) the osmotic data of Voigt et al (1990) for NaBr(aq) (at 100.3°C), of Fanghanel and Grojtheim (1990) for KBr(aq) (at 100.3°C) and of Hellams et al (1965) for KBr(aq) (at 45°C) are the only isopiestic method based data available in literature. Isopiestic results for the bromide solutions under investigation could not be found at temperatures below 25°C.…”

“…The water activity data (a w ) of Fanghanel and Grojtheim (1990) at 100.3°C and to 8.81 m KBr are also included in our data fit. With exception of the osmotic coefficients data of Patll et al (1991), all other activity data used in parameter's evaluation process are directly determined from isopiestic measurements of potassium bromide solutions.…”

“…The 25°C u values of Hamer and Wu (1972) are very close to the recommendations of Mikulin (1968) (to 5.5 m KBr) and the data of Robinson and Stokes (1949) (to 5.0 m KBr) and therefore last two sets of data are not included in our data fit. Note that in our final parameterization some of high concentration activity data points of Patll et al (1991) and of Fanghanel and Grojtheim (1990) …”