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Author Burns, J. D. ♦ Osborne, D. W. ♦ Westrum, E. F. (Jr.)
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ CALORIMETERS ♦ HEAT CAPACITY ♦ LOW TEMPERATURE ♦ MEASURED VALUES ♦ SCHOTTKY DEFECTS ♦ SPECIFIC HEAT ♦ THERMODYNAMICS ♦ THERMOMETERS ♦ URANIUM TETRAFLUORIDE
Abstract The heat capacity of uranium tetrafluoride was determined from 1.3 to 20 deg K in an isothermal calorimeter with an integral gas thermometer and vapor- pressure bulb for calibration of a carbon resistance thermometer. The enthalpy, entropy, and free-energy functions were evaluated from these data and previous measuremerts at higher temperatures. At 298.15 deg K the values of S deg , (H deg - H/sub 0/ deg )/T, and -(F deg - H/sub 0/ deg )/T are 36.25 plus or minus 0.04, 18.08 plus or minus 0.02, and 18.17 plus or minus 0.02 cal mole/sup -1/ deg -1/ for uranium tetrafluoride. A Schottky-type anomaly occurs in the heat capacity at 6.4 deg K, presumably as a consequence of ligand-field splitting of the electronic energy levels. (auth)
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1960-08-01
Publisher Department Argonne National Lab., Ill.
Journal Journal of Chemical Physics
Volume Number 33
Organization Argonne National Lab., Ill.


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