skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4

Abstract

High temperature heat capacity measurements were obtained for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} using a differential scanning calorimeter. These data were combined with previously-available, overlapping heat capacity data at temperatures up to 400 K and fitted to 5-parameter Maier-Kelley C{sub p}(T) equations. Expressions for molar entropy were then derived by suitable integration of the Maier-Kelley equations in combination with recent S{sup o}(298) evaluations. Finally, a database of high temperature equilibrium measurements on the formation of these oxides was constructed and critically evaluated. Gibbs energies of Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} were referenced by averaging the most reliable results at reference temperatures of 1100, 1400 and 1373 K, respectively, while Gibbs energies for ZnCr{sub 2}O{sub 4} were referenced to the results of Jacob [Thermochim. Acta 15 (1976) 79-87] at 1100 K. Thermodynamic extrapolations from the high temperature reference points to 298.15 K by application of the heat capacity correlations gave {Delta}{sub f}G{sup o}(298) = -1049.96, -1339.40, -1428.35 and -1326.75 kJ mol{sup -1} for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4}, respectively.

Authors:
Publication Date:
Research Org.:
Knolls Atomic Power Laboratory (KAPL), Niskayuna, NY
Sponsoring Org.:
USDOE
OSTI Identifier:
903084
Report Number(s):
LM-06K145
Journal ID: ISSN 0021-9614; JCTDAF; TRN: US200720%%73
DOE Contract Number:  
DE-AC12-00SN39357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Thermodynamics
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; ENTROPY; OXIDES; SPECIFIC HEAT; THERMODYNAMICS

Citation Formats

Ziemniak SE, Anovitz LM, Castelli RA, Porter WD. Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4. United States: N. p., 2007. Web. doi:10.1016/j.jct.2007.03.001.
Ziemniak SE, Anovitz LM, Castelli RA, Porter WD. Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4. United States. doi:10.1016/j.jct.2007.03.001.
Ziemniak SE, Anovitz LM, Castelli RA, Porter WD. Tue . "Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4". United States. doi:10.1016/j.jct.2007.03.001. https://www.osti.gov/servlets/purl/903084.
@article{osti_903084,
title = {Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4},
author = {Ziemniak SE, Anovitz LM, Castelli RA, Porter WD},
abstractNote = {High temperature heat capacity measurements were obtained for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} using a differential scanning calorimeter. These data were combined with previously-available, overlapping heat capacity data at temperatures up to 400 K and fitted to 5-parameter Maier-Kelley C{sub p}(T) equations. Expressions for molar entropy were then derived by suitable integration of the Maier-Kelley equations in combination with recent S{sup o}(298) evaluations. Finally, a database of high temperature equilibrium measurements on the formation of these oxides was constructed and critically evaluated. Gibbs energies of Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} were referenced by averaging the most reliable results at reference temperatures of 1100, 1400 and 1373 K, respectively, while Gibbs energies for ZnCr{sub 2}O{sub 4} were referenced to the results of Jacob [Thermochim. Acta 15 (1976) 79-87] at 1100 K. Thermodynamic extrapolations from the high temperature reference points to 298.15 K by application of the heat capacity correlations gave {Delta}{sub f}G{sup o}(298) = -1049.96, -1339.40, -1428.35 and -1326.75 kJ mol{sup -1} for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4}, respectively.},
doi = {10.1016/j.jct.2007.03.001},
journal = {Journal of Chemical Thermodynamics},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 09 00:00:00 EST 2007},
month = {Tue Jan 09 00:00:00 EST 2007}
}