Enthalpic pair-interaction coefficients between electrolytes and non-electrolytes in water and N N-dimethylformamide

HENRYK PIEKARSKI. Can. J. Chem. 64, 2127Chem. 64, (1986. Enthalpies of solution of NaCl in aqueous solutions of isopropanol, s-butanol, 2-methoxyethanol, 2-ethoxyethanol, acetone, and N,N-dimethylformamide were measured. The results of enthalpy measurements were analyzed from the point of view of the effect of added nonelectrolyte on water structure, and enthalpic pair interaction coefficients h,, {(Na' + C1-)-nonelectrolyte} were calculated and compared with appropriate data for (Na' + I-)-nonelectrolyte pairs. The group additivity concept appeared to be useful for the analysis of calculated h,, coefficients. The correlations between h,, and the functions characterizing different properties of the solutes under study were examined. It was shown that the correlation with the heat capacity of transfer of the nonelectrolyte molecule from the vapour phase to high dilution in water was the most promising. The interpretation of observed correlations was proposed.HENRYK PIEKARSKI. Can. J. Chem. 64, 2127Chem. 64, (1986. On a mesurC les enthalpies de solution du NaCl dans des solutions aqueuses d'isopropanol, de s-butanol, de mCthoxy-2 Cthanol, d'Cthoxy-2 Cthanol, d'acetone et de N,N-dimCthylformamide. On a analysC les rtsultats des mesures d'enthalpies en fonction de l'effet de I'addition d'Clectrolytes sur le structure de l'eau; de plus, on a calculC les coefficients d'interaction entre les paires enthalpiques [h,,{(NaL + C1)-nonelectrolyte}] et on les a cornparks avec les donnCes appropriCes relatives aux paires (Na+ + I)-nonelectrolyte. Le concept d'additivitk de groupe semble utile pour I'analyse des coefficients h,, calculCs. On a examink les corrClations qui existent entre h,, et les fonctions qui caractkrisent les diverses propriCtCs des solutes CtudiCs. On a dCmontrC que la corrClation avec la capacitC calorifique de transfert de la molCcule nonClectrolyte de la phase vapeur a une grande dilution dans I'eau est celle qui offre le plus de promesses. On propose une interpretation des corrilations observtes.[Traduit par la revue]Thermochemical properties of electrolyte solutions in the mixtures of water with nonelectrolytes are frequently studied in many scientific centres. The obtained results are explained from the point of view of mixed solvent structure as well as solute -mixed solvent interactions. Enthalpic pair interaction coefficients between the solute and cosolvent in solvent water are often regarded as a measure of the interactions that can appear in these systems (1). As it is known the above mentioned coefficients can be calculated among others from experimentally determined enthalpy of transfer of the solute from water to water-cosolvent mixture ( 2 , 3). From the numerous papers devoted to the analysis of the pair interaction coefficients, the most refer to the nonelectrolyte-nonelectrolyte pairs. Only a few papers concern the interactions between an electrolyte and a nonelectrolyte. One of them is a previous publication, prepared in our laboratory, that presents the systematic investigations of...

Section: Enthalpic Pair Interaction Coeficientsmentioning

confidence: 99%

Dissolution enthalpy of NaCl in aqueous nonelectrolyte solutions at 298.15 K. Analysis of electrolyte–nonelectrolyte enthalpic pair interaction coefficients in aqueous solution

Piekarski¹

1986

“…In such a case, hEN may be represented in the form of a summation [6] hEN C n E ; h E , where h E j is ;he characteristic contribution to coefficient h,, from mean ionic interactions with the selected group of type "i" in molecule "N". Following other authors (3,5,53,54), we assumed the CH3 group to be equivalent to 1.5 of the CH? group.…”

Section: E~zthalpic Pair Interaction Coefficientsmentioning

confidence: 99%

“…Enthalpic pair interaction coefficients in both two-and three-component systems have been dealt with in a number of studies, but few of them concerned interactions between electrolyte and nonelectrolyte (2)(3)(4)(5)(6). The aim of this study was to fill this gap, if only to some extent.…”

mentioning

confidence: 99%

“…As is well known, enthalpic interaction coefficients may be determined on the basis of dissolution enthalpies in a two-or three-component system (2)(3)(4)(5)7). Accordingly, the enthalpies of Nal dissolution in methanol, ethanol, propanol, isopropanol, and methoxyethanol + water mixtures were determined over the entire range of concentrations of the mixed solvent as well as in s-butanol and tert-butanol + water in the range of several mol% of alcohol at 298.15 K. Some of the above mentioned systems had previously been studied by calorimetric method (8)(9)(10)(11)(12).…”

mentioning

confidence: 99%

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Dissolution enthalpies of NaI in binary mixtures of water with aliphatic alcohols and methylcellosolve at 298.15 K. Enthalpic pair interaction coefficients of NaI–nonelectrolyte in water solution

Piekarski¹

1983

The enthalpy of solution, AH,,,,. of NaI in methanol + water, ethanol + water, 11-propanol + water, ~sopropanol + water, and methoxyethanol + water at all compositions and AH,,,, of NaI in s-butanol + water and ter-t-butanol + water from 0 to 5 mol% alcohol was measured.The NaI-nonelectrolytc pair interaction enthalpies were determined and correlated with the functions describing some properties of the nonelectrolyte. A functional group additivity concept, introduced by Savage and Wood for non-ionic solutes, was applied to thc interactions between NaI and nonelectrolytes.HENRYK PIEKARSKI. Can. J . Chem. 61, 2203 (1983).O n a mesuri I'enthalpie de solution AH,,, du NaI en solution dans les solvants suivants: methanol + eau, ithanol + eau, 11-propanol + eau, isopropanol + eau et mithoxyCthanol + eau en toutes proportions ct on a mesure le AH,,,' du NaI en solution dans les melanges de s-butanol eau et de tert-butanol eau dont la teneur en alcool varie de 0 i 5 mol%.O n a ditermini les enthalpies d'interaction de la paire: NaI-nonilectrolytc et on les a reliees aux fonctions qui dicrivent certaines proprietis d'un non ilectrolyte. O n a applique un concept d'addiv~te de groupe fonctionnel, introduit par Savage et Wood pour les solutes non ioniques, aux ~nteractions entre le NaI ct les non ilectrolytes.[Tradu~t par le journal]

“…The group additivity concept developed by Savage and Wood (6) to correlate enthalpic pair interaction coefficients of a wide range of nonelectrolytes (mainly alcohols, polyhydroxy compounds, and amides) in water has been found to be very useful in predicting unknown values. A similar group additivity concept was employed by Heuvelsland, D e Visser, and Somsen (16) to the analysis of interactions in systems containing ionic solutes (tetraalkylammonium bromides) in water as well as in the nonaqueous solvent N,N-dimethylformamide (DMF). Also the enthalpic interaction coefficients for Nal-alcohol pairs in aqueous solution appeared to be a sum of group contributions (17).…”

Section: Introductionmentioning

confidence: 99%

Enthalpies of solution of urea in water–alkanol mixtures and the enthalpic pair interaction coefficients of urea and several nonelectrolytes in water

Piekarski¹,

Somsen²

1986

HENRYK PIEKARSKI and Gus SOMSEN. Can. J. Chem. 64, 1721Chem. 64, (1986. Enthalpies of solution of urea in binary mixtures of isopropanol, s-butanol, and ethoxyethanol with water have been measured at high water content. Those in the binaries isopropanol + water and ethoxyethanol + water show endothermic maxima at 8 and 4 mol% alkanol, respectively. Enthalpic pair interaction coefficients are calculated for the interactions between urea and the alkanols and discussed in connection with these coefficients for interactions between urea and other nonelectrolytes and between N,N-dimethylformamide and several nonelectrolytes. The enthalpic pair interaction coefficients correlate linearly with the heat capacity change on hydration of the nonelectrolytes and with the enthalpy of hydrophobic hydration of the alkanols.