Activity Coefficients of NaCl in Aqueous Mixtures with High Relative Permittivity Cosolvent: Ethylene Carbonate + Water at 298.15 K

Abstract

The mean ionic activity coefficients of NaCl were experimentally determined in ethylene carbonate (EC) + water at 298.15 K from potential difference measurements of the following electrochemical cell containing two ion-selective electrodes (ISEs):The molality (m) varied between 0.02 mol • kg -1 and almost saturation, while the mass fraction of EC in the mixture (w) was varied between 0 and 0.8 in 0.1 unit steps. Values of the standard potential difference, E 0 (molal scale), were determined using a routine method of extrapolation together with the extended Debye-Hu ¨ckel, Pitzer, and Scatchard equations. The results obtained produced good internal consistency, within the normal limits of experimental error encountered in these types of measurement. Once E 0 was determined, the mean ionic activity coefficients of the NaCl, the Gibbs energy of transfer of the NaCl from the water to the EC + water mixture, standard solubility product of NaCl in EC + water, and the NaCl primary hydration number were estimated. The results were comparatively analyzed with those of the NaF previously obtained in similar mixtures.

Density, Viscosity, and Conductivity of Binary Mixtures of the Ionic Liquid N-(2-Hydroxyethyl)piperazinium Propionate with Water, Methanol, or Ethanol

“…In addition, the k values for the binary system with water are larger than those with alcohols. The electric conductivity decreases with the decreased solvent permittivity (ε r ) in the following order: water (ε r = 78.38) > methanol (32.64) > ethanol (24.55). − The polarity of water is much higher than that of alcohols as well with the order of water (10.2) > methanol (6.6) > ethanol (4.3), thus the electrolyte is easier to dissociate into ions in water, facilitating the charge movement, and eventually, the electrical conductivity is elevated.…”

Activity Coefficients of NaCl in Ethylene Glycol‐Water Mixtures Using Potentiometric Measurements at 288.15, 298.15 and 308.15 K

“…For example, Lopes et al 3 obtained mean activity coefficients of NaCl in ethanol-water mixtures. Hernández-Luis et al 4,5 investigated the activity coefficients for NaCl in ethylene carbonate/PEG 4000-water mixtures at 298.15 K. Zhuo et al 6 investigated the activity coefficients for NaClmonosaccharide (D-glucose, D-galactose, D-xylose, D-arabinose)-water systems at 298.15 K, moreover they determined activity coefficients for NaBr in aqueous D-trehalose/D-cellobiose solutions at 298.15 K. 7 Dinane et al 8 calculated the activity coefficients of NaCl in MgCl 2 -water system.…”

Activity Coefficients in Quaternary Systems at 298.15 K: RbCl + MeOH + EtOH + H2O and CsCl + MeOH + EtOH + H2O Systems

“…Moreover, the variation trend of ( a – q ) with the reciprocal of the relative permittivity is lightly decreased. This phenomenon is the same as that in system NaCl/NaF + EC + H 2 O , but different from that in CsBr + MeOH/EtOH + H 2 O systems …”

“…In the literature, there are numerous studies of alkali halides in organic–water mixtures by potential difference measurements, for example, KCl and NaCl in ethanol–water, , NaCl/NaF in methanol/ethanol–water, , NaF/NaCl/NaBr in fomamide–water, − NaF/NaBr/NaCl in ethylene carbonate–water, − NaCl/KCl/LiCl in PEG 4000-water. − However, only a few studies are cited in the literature that describe the mean activity coefficients of alkali halides in ternary mixed solvents from potentiometric data …”