ISSN:
1572-8927
Keywords:
Apparent molal enthalpy
;
apparent molal heat capacity
;
tetrabutylammonium butyrate
;
aqueous
;
solutions
;
calorimetry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Enthalpies of dilution of tetrabutylammonium butyrate are reported as a function of temperature between 10° and 50°C. Heat capacities of aqueous solutions of tetrabutylammonium butyrate were measured in order to obtain values ofφ cp at 15°, 25°, and 35°C. These data were combined with the enthalpy of dilution data to obtain φcp as a function of molality and temperature. The apparent molal heat content φL decreased with increasing temperature in concentrated solutions but increased with increasing temperatures in dilute solutions (below0.7 m). Over the temperature range studied φcp shows a maximum as a function of molality at approximately 0.5m. The decrease in φcp with increasing concentration of hydrophobic solute is consistent with the view that the hydrophobic hydration cages, formed under the influence of the tetrabutylammonium and butyrate ions, are saturated at about 0.5m, and that at higher molalities increased overlap of the hydration cages occurs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00651006
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