The Thermodynamic Properties of High Temperature Aqueous Solutions. I. Standard Partial Molal Heat Capacities of Sodium Chloride and Barium Chloride from 0 to 100°<sup>1</sup>

Uses of heat capacities of solutions of electrolytes are reviewed, with a particular emphasis on the standard state partial molar heat capacities and their applications to calculations of the effects of temperature on equilibrium constants, electrode potentials, enthalpies, and entropies. Methods of obtaining these standard partial molar heat capacities are summarized, followed by comparisons of values obtained in different ways. Many of the "best" such heat capacities are collected and then used as the basis for establishing single-ion heat capacities based on the convention that c p O (~+ ) = 0, followed by illustrations of the convenient use of these quantities. Finally, there is brief discussion of theoretical analysis of these standard partial molar heat capacities in relation to ion-solvent interactions.Key words: heat capacities, electrolytes; aqueous solutions, heat capacities; thermodynamics, electrolytes.RCsumC : On prksente une revue de l'utilisation des capacitCs calorifiques de solutions d'Clectrolytes en insistant d'une faqon particuliere sur les capacites calorifiques molaires partielles dans 1'Ctat standard et leurs applications aux calculs des effets de la temperature sur les constantes d'equilibre, les potentiels d'klectrode, les enthalpies et les entropies. On rksume les methodes d'obtenir ces capacites calorifiques molaires partielles standard et on prksente ensuite un comparaison des diverses valeurs obtenues d'aprks les diverses manieres. Plusieurs des ccmeilleuresa propriCtCs, comme les capacitks calorifiques, ont CtC rassemblCes et ont ensuite Ct C utilisees comme base pour I'Ctablissement des capacitks calorifiques d'un seul ion en se basant sur la convention que c,' (H+) = 0; elles sont suivies par des illustrations sur l'utilisation commode de ces quantitks. Enfin, on presente une breve discussion de I'analyse thiorique de ces capacitks calorifiques molaires partielles standard en relation avec les interactions ion-solvant.

Section: Experimental and Calculation Methodsmentioning

confidence: 81%

Section: Experimental and Calculation Methodsmentioning

confidence: 90%

Section: Experimental and Calculation Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Standard state heat capacities of aqueous electrolytes and some related undissociated species

Hepler¹,

Hovey²

1996

“…The measured enthalpies of solution were extrapolated to infinite dilution by the method of Criss and Cobble (4). The dielectric permittivity and the density of water-alcohol mixture were adopted from the literature (5, 6).…”

Section: Solution Enthalpymentioning

confidence: 99%

Dissolution enthalpy of NaI in water–alcohol mixtures at 288.15 and 308.15 K. Enthalpy of interaction in electrolyte–alcohol–water systems

Piekarski¹,

Piekarska²,

Taniewska-Osińska³

1984

HENRYK PIEKARSKI. ALINA PIEKARSKA, and STEFANIA TANIEWSKA-OSINSKA. Can. J. Chem. 62, 856 (1984).The enthalpy of Nal solution was determined in water mixtures with methanol, ethanol, propanol, and isopropanol in the entire range of mixed-solvent concentration at 288.15 and 308.15 K,-and in water mixtures with s-butanol and tert-butanol in the range of 0-5 mol% alcohol at 308.15 K. The dependence of c::? on solvent composition was studied. The cnthalpic pair interaction coefficients hEN for Nal-alcohol in water and Nal-water in alcohols were determined, and the effect of temperature on llEN values in the systems under study was analyzed. Introduction While calorimetric investigations of electrolyte solutions in water -aliphatic alcohols have often been conducted at various laboratories, there is little data on the effect of temperature on the thermochemical properties of electrolyte-alcoholwater systems in the whole range of mixed-solvent composition (1). In view of this we decided to measure the enthalpy of NaI solution in methanol, ethanol, propanol, and isopropanol mixtures with water over the entire range of mixed-solvent concen-

“…to 1 X M. All data are extrapolated to infinite dilutions using the extended DebyeHiickel equation (3). The advantage of using this equation is discussed in detail by Criss and Cobble (7). The standard enthalpies of solution (AH,") of the electrolytes from this study as well as from previous studies are summarized in Table 1.…”

Section: Apparcrrus and Proceduresmentioning

confidence: 93%

Enthalpies of solution and single ion enthalpies of transfer from water to dioxane–water mixtures

Bhatnagar¹

1976

OM N. BHAT~AGAR Can J. Chem 54, 3487 (1976) Standard enthalples of solutions of sodlum bromlde, potasslum bronude, tetrabutyl phosphonium brom~de, tetraphenyl phosphoniu~n bromide, and sodlum tetraphenyl boron have been measured In 20C,, 44 5' ,, and 64 5(, dloxane-water mlxture. On the extra thermodynam~c assumption AAH,(Ph4P+) = AAH,(-BPh4) slngle Ion enthalples of tranifer from water to d~oxane-water mixtures have been calculated for \ arlous Ions.OM N. BHATNAGAR. Can. J. Chem. 54, 3487 (1976). On a mesurC les enthalpies standards de solution du bromure de sodium, du bromure de potassium, du bromure de tCtrabutylphosphonium, du bromure de tCtraphCnylphosphoniun~ et du tCtraphCnylbore sodium dans des mClanges dioxanne-eau k 20C$, 44.5C; et 64.5yc. En faisant I'hypothkse thermodynamique supplCmentaire que AAH,(Ph4P+) = a~H , ( -B p h~) , on a calcule, pour divers ions, les enthalpies de transfert d'ions uniques de I'eau a des melanges dioxanne-eau.[Traduit par le journal] Introduction I have been interested in the study of thermodynamic properties of electrolyte solutions in dioxane-water mixtures for some time (1-3). The solvation enthalpies of some tetraalkyl ammonium bromides in dioxane-water mixtures were reported in a recent paper (3). It was shown that the behaviour of these electrolytes was quite similar to their behaviour in water and that the structure-making capacity of tetraalkyl ammonium ions increases with the increase in the size of the ion. Thus from the studv in dioxanewater mixtures Bu4N+ ion was found to be the most active in structure promotion. It was thought to be of interest to see how this behaviour would change (i) by changing the central atom from nitrogen to phosphorus, (ii) by changing the nature of tetraalkyl ion from aliphatic ( [ G H 9]4-) t o aromatic ([C6H5]4-), (iii) by changing the small Br-ion to a bulky -BPh4 ion.In this paper the standard enthalpies of solution, AHsO, of sodium bromide, potassium bromide, tetrabutyl phosphonium bromide (BudPBr), tetraphenyl phosphonium bromide ([C6H5]4PBr) and sodium tetraphenyl boron (NaBPh4) in 207,, 44.57,, and 64.57, dioxane-water mixtures are reported. In addition, an attempt has been made to divide the standard enthalpies of transfer AAH, from water to dioxane-water mixtures into