SOME THERMAL AND PHOTOCHEMICAL STUDIES OF THE FERRIOXALATE COMPLEXES.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1961
- Accession Number
- AD0478200
Entities
People
- John B. Holden Jr.
Organizations
- Princeton University