Thermodynamics of the lanthanide trifluorides. I. The heat capacity of lanthanum trifluoride, LaF/sub 3/ from 5 to 350/sup 0/K and enthalpies from 298 to 1477/sup 0/K
The heat capacity of a sample of LaF/sub 3/ was determined in the temperature range 5--350/sup 0/K by aneroid adiabatic calorimetry and the enthalpy from 298.15 to 1477/sup 0/K by drop calorimetry. The heat capacity at constant pressure C/sup 0//sub p/(298.15/sup 0/K), the entropy S/sup 0/ (298.15/sup 0/K), the enthalpy (H/sup 0/ (298.15/sup 0/K)-H/sup 0/ (0)) and the Planck function -(G/sup 0/ (298.15/sup 0/K)-H/sup 0/ (0))/298.15/sup 0/K; were found to be (90.29 +- 0.09) J /sup 0/K/sup -/1xmole/sup -/1, (106.98 +- 0.11) J /sup 0/K/sup -/1xmole/sup -/1, (16717 +- 17) J mole/sup -/1, and (50.91 +- 0.05) J /sup 0/K/sup -/1xmole/sup -/1. The thermal functions from the present research were extended up to the melting temperature (1766/sup 0/K) by combination with previously published results. The anomalously high heat capacity from about 1100 to 1766/sup 0/K is discussed.
- Research Organization:
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
- OSTI ID:
- 7063773
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 69:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermodynamics of the lanthanide trifluorides. II. The heat capacity of praseodymium trifluoride PrF/sub 3/ from 5 to 350 /sup 0/K
Enthalpies of formation of low albite (NaAlSi/sub 3/O/sub 8/), gibbsite (Al(OH)/sub 3/), and NaAlO/sub 2/; revised values for. delta. H/sub f 298//sup 0/ and. delta. G/sub f 298//sup 0/ of some aluminosilicate minerals