The Activity Coefficient of Potassium Chloride in Aqueous Solutions at 0° from Electromotive Force and Freezing Point Data

Freezing point, viscosity, and boiling point data are presented for aqueous solutions of levo-2,3-butanediol containing methanol, ethanol, ethylene glycol, and tetrahydrofurfuryl alcohol as third components. All four ternary systems show freezing points of −50 °C. and lower over a considerable range of compositions. Among the compounds tested as third components, methanol was most effective as a thinning agent and accessory freezing point depressant. The data indicate that 20% methanol–40% butanediol–40% water is suitable for use at temperatures as low as −50 °C.

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A study of ionic association in aqueous solutions of bi-bivalent electrolytes by freezing-point measurements

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1955.0221 ◽

1955 ◽

Vol 232 (1190) ◽

pp. 320-336 ◽

Cited By ~ 50

Keyword(s):

Aqueous Solutions ◽

Potassium Chloride ◽

Dissociation Constants ◽

Freezing Point ◽

Ionic Association ◽

Freezing Point Depression ◽

Physical Status ◽

Copper Zinc ◽

Cobalt And Nickel

Measurements of freezing-point depression with a precision of ± 0-0002° C have been made on aqueous solutions of potassium chloride and the sulphates of copper, zinc, magnesium, calcium, cobalt and nickel. The results for the sulphates have been analyzed using the theory of incomplete dissociation in a manner which makes clear the physical status of the dissociation constants obtained, and the relation between the approaches associated with the names of Bjerrum and Davies. The values of the dissociation constants are compared with those obtained by other methods.

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Thermodynamics of micellar systems: activity and entropy of sodium decanoate and n-alkylamine hydrobromides in water

Canadian Journal of Chemistry ◽

10.1139/v81-278 ◽

1981 ◽

Vol 59 (13) ◽

pp. 1865-1871 ◽

Cited By ~ 20

Author(s):

Rosario De Lisi ◽

Gérald Perron ◽

Jean Paquette ◽

Jacques E. Desnoyers

Keyword(s):

Heat Capacity ◽

Aqueous Solutions ◽

Homologous Series ◽

Freezing Point ◽

Activity Data ◽

Micellar Systems ◽

Point Data ◽

Sodium Decanoate ◽

Capacity Data ◽

Mean Activity Coefficients

The freezing-point depressions of aqueous solutions of the homologous series RNH3Br, where R varies from ethyl to n-octyl, and of sodium decanoate were determined and used to calculate osmotic and mean activity coefficients. In the case of the surfactants octylamine hydrobromide and sodium decanoate, the pre- and post-micellar regions were covered. Activity data at higher temperatures were calculated using previously published thermochemical data. Some difficulties arise in the critical micellar region of sodium decanoate at high temperatures as a result of the large concentration and temperature dependence of the heat capacity data. The activities from freezing point data are compared with those obtained from specific electrodes.

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