Heats of mixing of aqueous electrolytes : temperature dependence

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Linda Anne Petree (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Henry Anderson

Abstract: The heats of mixing of aqueous electrolytes provide an excellent method of studying specific ion interactions. Numerous systems have been studied at 25°, but as yet few measurements have been made at elevated temperatures. In order to extend the thermodynamic calculations and further the knowledge of solute-solvent interactions, a study of systems at temperatures other than 25° is necessary. The heats of mixing for the systems NaCl-HCl-H20, NaCl-LiCl-H20, NaCl-KCl-H20, and LiCl-KCl-H20 at 1.0 molal and LiCl-(CH3)4NCl-H20 and KC1-(CH3)4NC1-H20 at 0.5 molal and constant ionic strength were measured at 40, 60, and 80°. An isothermal, double microcalorimeter was used for the experimental work. The heat of mixing for systems involving the Na ion showed temperature dependence, but the other systems had heats of mixing independent of temperature. It is postulated that the heat of mixing is mainly influenced by interactions occurring in the water which is at the interface of the primary and secondary hydration spheres of the ions.

Additional Information

Language: English
Date: 1970
Electrolytes $x Thermal properties
Electrolyte solutions

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