Accession Number : AD0478200

Title :   SOME THERMAL AND PHOTOCHEMICAL STUDIES OF THE FERRIOXALATE COMPLEXES.

Descriptive Note : Doctoral thesis,

Corporate Author : PRINCETON UNIV N J

Personal Author(s) : Holden,John B. ,Jr.

Report Date : JUN 1961

Pagination or Media Count : 182

Abstract : The thermal and photochemical decomposition of iron(III) oxalates have been studied in aqueous solution and in complex salts. The thermal decomposition of K3Fe(C2O4)3.3H2O was studied in air and under vacuum by thermogravimetric techniques. The solids remaining, as well as the gaseous products, were identified for each step of these decompositions by means of x-ray diffraction, mass spectroscopy, and weight loss. In addition, a kinetic study of certain steps in these thermal decompositions was made. Photolytic decomposition of dehydrated K3Fe(C2O4)3 was studied with both broadband and filtered ultraviolet radiation. No completely definitive analysis of the reaction or the decomposition products was made but it was shown that the results are consistent with the exciton theory of photodecomposition. The rate of iron(II) production was used to follow the thermal decomposition of the oxalate complexes of iron(III) at various temperatures in aqueous solutions. In order to interpret these data, the concentration were evaluated by computer techniques. In the photochemical decomposition of solutions of the iron(III) oxalates, the explanation of the results require knowledge of the absorption spectra of the various iron(III)-oxalate complexes. A simple method was devised whereby the entropy of complex formation, can be estimated. Calculations, using the entropy values in the standard references and those attainable from statistical mechanics, for systems for which delta S (super zero) is known, has led to values of the entropy of hydration of complexes. These values have shown trends which can be correlated to the ability of the complex to orient water molecules. (Author)

Descriptors :   (*COMPLEX COMPOUNDS, REACTION KINETICS), (*THERMOCHEMISTRY, COMPLEX COMPOUNDS), (*PHOTOLYSIS, COMPLEX COMPOUNDS), THERMODYNAMICS, SOLUTIONS(MIXTURES), IRON COMPOUNDS, OXALATES, SOLIDS, HYDRATES, THERMOGRAVIMETRIC ANALYSIS, X RAY DIFFRACTION, MASS SPECTROSCOPY, QUANTITATIVE ANALYSIS, ENTROPY, CONCENTRATION(CHEMISTRY), CHEMICAL EQUILIBRIUM, DIFFERENTIAL THERMAL ANALYSIS, COMPUTERS, DEHYDRATION, REDUCTION(CHEMISTRY), ABSORPTION SPECTRA, LIGHT, APPROXIMATION(MATHEMATICS), PYROLYSIS

Subject Categories : Radiation and Nuclear Chemistry
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE