D. W. Osborne, F. Schreiner, H. Flotow
Oct 15, 1972
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Influential Citations
37
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Journal
Journal of Chemical Physics
Abstract
The heat capacity of a very pure sample of xenon tetrafluoride, XeF4, was determined by adiabatic calorimetry between 5 and 350°K. No irregular thermal behavior was observed, except in the region near 210°K, where slightly enhanced heat capacity values, ascribed to a small amount of impurity, were observed. The values of the thermodynamic quantities Cp°, S°, (H° − H °0)/T, and (G° − H °0)/T at 298.15°K are 118.39 ± 0.12, 167.00 ± 0.17, 77.24 ± 0.08, and −89.76± 0.09 J °K−1 · mole−1, respectively. The standard entropy of the gas at 298.15°K was calculated from the thermal data to be 323.2± 2.0 J °K−1· mole−1, in excellent agreement with the value 323.98 ± 0.4 J °K−1· mole−1 calculated from electron‐diffraction data and the frequency assignment of Tsao, Cobb, and Claassen. The standard entropy of formation of solid XeF4 at 298.15°K was found to be −407.95 ± 0.17 J °K−1 · mole−1, and the standard Gibbs energy of formation at 298.15°K is −145.48 ± 0.88 kJ mole−1. The corresponding quantities for gaseous XeF4 ...