Thermodynamic properties of the dilute solutions of silver chloride and aluminum trichloride in alkali chlorides by electromotive force measurements

Abstract

P. J. TUMIDAJSKI and S. N. FLENCAS. Can. J. Chem. 63, 1080 (1985.'Thermodynamic data for dilute solutions of AgCl and AlCl, in molten alkali chlorides were derived from the emf's of formation and of galvanic cells, respectively, given as, Ag/AgCI -ACI/C,C12 and Ag/AgCl -ACI//AIC13 -ACI/AI. ACI represents NaCI, KC1, CsC1, or the equimolar mixtures of NaCI-CsCI and KC1-CsCI. It was found that the thermodycmic properties o m e ternarymelts could be predicted from the results of the binary melts using the relationship (17,20,21), (AZ),,, = (1 -t) (AZ),, + t(AZ),,, where Z represents any partial molar property. The ternary solution is denoted by the subscript 1, 2, 3 while the two binaries are denoted by 1, 2 and 1, 3; t is a concentration variable given as t = X3/(X2 + X,). These expressions are valid when the binary and the ternary solutions have the same content of either AgCl or AlCI,, respectively. P. J . TUMIDAJSKI et S. N. FLENCAS. Can. J . Chem. 63, 1080Chem. 63, (1985.En se basant sur les fem de formation et des cellules galvaniques Ag/AgCl -ACI/C, C12 et Ag/AgCI -AC1//AIC13 -ACl/Al dans lesquelles ACI reprtsente NaCI, KC1, CsCl ou des mtlanges Cquimolaires de NaCI-CsC1 ou de KCI-CsCI, on a tvalut les donntes thermodynamiques de solutions dilutes de AgCl et de AlC13 dans des chlorures alcalins fondus. On a trouvC que l'on peut prtdire les proprittts thermodynamiques des selsgrnaires fondus e n s b a s a n t s~l e s rtsultats obtenus avec des sels binaires fondus et en utilisant la relation (17, 20, 21) (AZ)123 = (1 -t) (AZ),? + t(AZ)13, oh Z reprtsente n'importe quelle propriktt molaire partielle. On utilise les indices 1, 2, 3 pour dtsigner la solution ternaire et les indices 1, 2 et 1, 3 pour designer les deux solutions binaires; t est une variable de concentration que l'on reprtsente par t = X3/(X2 + X,). Ces expressions sont valables quand les solutions ternaires contiennent chacune des quantitts semblables de AgCl ou de AICI,. [Traduit par le journal]Introduction The thermodynamic properties of the solutions of AgCl or AlCl, in alkali chloride melts have been the subject of several studies. For the former, the systems investigated include the binary solutions of AgC1-NaCl (1 -3), AgCl-KC1 (1, 3, 4), AgCI-CsCl (1, 3) and AgCl-RbCl (3), and the ternary solutions of AgCl-LiCl-KC1 (5, 6 ) , AgCl-NaCI-KC1 (3), and AgC1-NaC1-CsC1 (3). For the case of AlCl,, the following systems have been studied: AlC1,-NaCI (7-12), AlC1,-KC1 (7), AIC1,-RbCl (7), AlC1,-CsCl (7), and AlC1,-NaCl-KC1 (13). These measurements were taken with concentrated solutions of AgCl or AlCl,. The behaviour of dilute solutions of AgCl or AlCl, where Henry's law is expected to be valid have not yet been investigated. The thermodynamic properties of the dilute solutions of AgCl in the binary systems AgCl-NaCl, AgCl-KCl, AgCl-CsCl, and in the ternary systems AgC1-NaC1-CsC1 and AgCl-KCl-CsCl have been obtained from emf measurements on formation cells of the type, Ag/AgCl -ACl/C,CI,. The thermodynamic properties of the dilute solutions of AlCl,...

Thermodynamic properties of the NiCl2–CoCl2–KCl system

“…Reversibility was confirmed by temperature cycling and with polarization tests. For a complete description of the temperature cycling procedure and the polarization test refer to previous reports (1,4). In all cases, the cell EMF returned to within 5 2 mV of the original cell EMF.…”

“…The cell design was similar to the chloride formation cells described elsewhere (3,4,7). The cell consisted of a nickel metal electrode immersed in the NiC1,-CoC1,-KC1 molten solution of known composition and a graphite chlorine electrode which also dipped into a molten solution of the same composition.…”

“…In previous publications from the authors, the thermodynamic properties of charge asymmetric molten salt solutions of metal chlorides with alkali halide solvents have been investigated by EMF measurements (1)(2)(3)(4)(5)(6)(7). The measurements provide valuable and practical information on: the feasibility of new pro-high-temperature batteries and energy storage devices.…”

Potential Measurements of Reactive Metal Chlorides in Alkali Halide Solutions: I . Silver, Cobalt, Nickel, Iron, and Copper

“…In previous publications from this laboratory, the thermodynamic properties of solutions of metal chlorides in alkali chloride solvent melts have been investigated by EMF measurements (1)(2)(3)(4)(5)(6)(7)(8). The data have been used for the calculation of activities and other partial molar properties.…”

“…1. Details have been reported elsewhere (8,12). The cell consisted of two half-cell compartments separated by an asbestos diaphragm made by tightly rolling a small strand of asbestos fibers, firing to a white ash, and then collapsing 6 mm quartz tubing around it.…”