Activity coefficients of alkyl acetates in concentrated electrolyte solutions

Abstract

The activity coefficients of methyl acetate (MeOAc), ethyl acetate (EtOAc), n-propyl acetate (n-PrOAc), n-butyl acetate (n-BuOAc), and n-pentyl acetate (n-PeOAc) have been measured at 25 °C in concentrated aqueous solutions of electrolytes using the distribution technique. The salts used were LiCl, NaCl, KC1, CsCl, KF, KBr, NaNOg, and NaC104. In general, the results obtained are as might be expected. A mechanistic explanation is given of the trends observed and unexpected features in the data are explained with the aid of some assumptions regarding the nature of ionic hydration. The apparent molar volumes of MeOAc have also been determined over the full range of molalities for each of the salts used in the activity coefficient determinations. These measurements are then used in conjunction with thermodynamic data for the salt solutions (from the literature) to calculate the MeOAc activity coefficients according to the expanded McDevit and Long equations developed in an earlier publication. Similar, but less accurate calculations have also been done for the activity coefficients of the larger esters. In these cases, apparent molar volumes were determined only in water. The calculations are found to have mixed success.

Single-ion Setschenow coefficients for several hydrophobic non-electrolytes in aqueous electrolyte solutions

“…Our results are compatible with k, values obtained by earlier workers for aromatic non-electrolytes in alkali and tetraalkylammonium halide solutions (1)(2)(3)(4)(5)12). The data in this table provide a reasonably self-consistent assembly according to the "additivity rule", and it is thus not unreasonable to attempt to dissect the k, values for the electrolytes into single ion values.…”

“…Several theories have been used to characterise the essential features of the salting phenomenon (1)(2)(3). The influence of a salt on the solubility of a non-electrolyte is usually characterised and quantified by the Setschenow coefficient, or salting constant, k,.…”

Influence of inorganic salt on the effectiveness of liquid mixtures separation by pervaporation☆

“…6). In the case of water-MeAc-NaCl Table 2 Activity coefficient of MeAc in the aqueous NaCl solutions [42] NaCl concentration (mol NaCl/kg water) ternary system, MeAc solubility in water drops from 23.9 wt.% in pure water to 14.8 wt.% in 1 M NaCl aqueous solution [40]. According to the Eq.…”

“…7. Influence of the NaCl concentration of the relative fluxes and relative activity coefficients [42] in water-MeAc-NaCl ternary system. ues of log([J MeAc /J water ]/[J 0 MeAc /J 0 water ]) were plotted as a function of NaCl concentration and compared with data for the activity coefficient (Table 2; [42]).…”

“…Influence of the NaCl concentration of the relative fluxes and relative activity coefficients [42] in water-MeAc-NaCl ternary system. ues of log([J MeAc /J water ]/[J 0 MeAc /J 0 water ]) were plotted as a function of NaCl concentration and compared with data for the activity coefficient (Table 2; [42]). The data for log([J MeAc /J water ]/[J 0 MeAc /J 0 water ]) versus C NaCl are linear for NaCl concentration up to 2 mol dm −3 , with the pervaporation k s(PV) coefficient equals 0.151 (dm 3 mol −1 ).…”