Heats of dilution of sodium chloride temperature dependence

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

Abstract: The recent increase of interest in high temperature thermodynamic data has revealed that very little precise data exists. Also, the data that does exist contains some large uncertainties. An efficient and accurate method is needed by which high temperature thermodynamic data can be obtained. This is essential not only for extending the present knowledge of aqueous electrolyte solutions, but also to remove the uncertainties now existing in published data. The heats of dilution of sodium chloride have been measured over a concentration range of 0.1 m to 6.0 m at 40°, 50°, 60°, 70°, and 80° . These measurements were made using a micro-degree calorimeter. The experimental data was extrapolated to infinite dilution using the extended Debye-Hückel equation. The partial molal heat contents of solute and solvent were calculated from the experimental heats of dilution. These values in turn were used to correct existing activity coefficients and osmotic coefficients at 25° to higher temperatures. The calculated values were found to be in excellent agreement with existing data. The apparent molal heat capacity of solute was also calculated from partial molal heat content of solute; however, no real conclusions as to the accuracy of these values could be reached. It is concluded that use of heat of dilution data to correct existing values of thermodynamic quantities to higher temperatures is an efficient and precise technique.

Additional Information

Language: English
Date: 1972
Electrolytes $x Thermal properties
Salt $x Experiments

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