THE CR-CR2O3 OXYGEN BUFFER AND THE FREE-ENERGY OF FORMATION OF CR2O3 FROM HIGH-TEMPERATURE ELECTROCHEMICAL MEASUREMENTS

被引：29

作者：

HOLZHEID, A ^{[1
]}

ONEILL, HS ^{[1
]}

机构：

[1] MAX PLANCK INST CHEM,D-55020 MAINZ,GERMANY

来源：

GEOCHIMICA ET COSMOCHIMICA ACTA | 1995年 / 59卷 / 03期

关键词：

D O I：

10.1016/0016-7037(94)00287-V

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The free energy of formation of Cr2O3, defined by the reaction 2 Cr + 3/2 O-2 = Cr2O3, has been measured electrochemically using a yttria-doped thoria (YDT) solid electrolyte, in the temperature range from 900 to 1400 K. Fe + ''FeO'' was used as the reference electrode. The results have been combined with high temperature heat capacity data from the literature, to give, in J.mol(-1) mu O-2(+/-170) = -758,585 + 349.718T - 25.5216T In T + 0.00935T(2) (600 K < T < 1800 K). Our results are not in good agreement with the calorimetric data and imply that the currently accepted calorimetric value for the entropy of Cr2O3 at 298.15 K may be too low by 4.6 J/K.mol.

引用

页码：475 / 479

页数：5

共 16 条

[1] The heat capacities of chromium, chromic oxide, chromous chloride and chromic chloride at low temperatures [J].