Activity Coefficients of RbF or CsF in the Ethene Glycol + Water System by Potentiometric Measurements at 298.15 K

Abstract

In this work, we report the measurements of the thermodynamic properties of RbF or CsF in the ethene glycol + water system at 298.15 K in the range of w = 0.10 to 0.40 ethene glycol. The experimental data were calculated by Pitzer model. Standard cell potentials and Pitzer parameters were obtained. From these, mean activity coefficients of RbF or CsF, osmotic coefficients of the mixtures, and standard Gibbs energies of transfer of RbF or CsF from water to ethene glycol + water mixtures were calculated.

Activity Coefficients for CsBr + MeOH/EtOH + H2O Ternary Systems Using Potentiometric Measurements at 298.15 K

“…In the previous study, we reported the activity coefficients of LiCl, RbCl, CsCl, RbF, and CsF in alcohol–water mixtures. ,− As an extension of our work, the ternary systems CsBr–MeOH–water and CsBr–EtOH–water at 298.15 K were studied in this paper. The activity coefficients (γ ± ), osmotic coefficients (Φ), excess Gibbs free energies ( G E ), and standard Gibbs energies of transference (Δ G t 0 ) for CsBr in MeOH–water and EtOH–water mixed solvent systems are presented, while the mass fraction of alcohol in the mixture ( w ) was varied between 0 and 0.3.…”

Pitzer, Modified Pitzer, and Extended Debye–Hückel Modeling Approaches: Ternary RbF or CsF + Glycine + Water Electrolyte Systems at 298.15 K

“…Water used in experiment was doubly distilled water, and the specific conductance was approximately (1.0 to 1.2)·10 –4 S·m –1 . Details of the potentiometric measurements and general techniques were the same as previously described in our previous work. , …”

“…Details of the potentiometric measurements and general techniques were the same as previously described in our previous work. 16,17 The Rb ion-selective electrode (Rb-ISE) and Cs ion-selective electrode (Cs-ISE) were a PVC membrane type based on valinomycin and were filled with 0.10 mol•L −1 RbF or CsF as the internal liquid in K ion-selective electrode. Both the membrane electrode and the F-ISE (model 201) were obtained from Jiangsu Electroanalytical Instrument Co., and the electrodes were calibrated before the experiment and showed a good Nernstian response.…”

“…13 Zhuo et al determined the thermodynamic properties for CaCl 2 in (glycine, alanine, serine, or proline + water) mixtures at T = 298.15 K. 14,15 In our previous work, we obtained the mean activity coefficients of RbCl and CsCl in glycine + water mixtures and RbF and CsF in ethylene glycol + water. 16,17 As an extension of our series of works on the thermodynamic properties of unusual alkali metal salts in the mixed solvent system, 16,17 this paper investigated the ternary systems RbF or CsF + glycine + H 2 O. The mean activity coefficients, the osmotic coefficients, the excess Gibbs free energy, and the standard Gibbs energies of transfer of the systems were reported.…”