Oxidation ofiron

This balanced equation can be read as 4 iron atoms react with 3 oxygen molecules to produce 2 iron(III) oxide units. However, the coefficients can stand not only for the number of atoms or molecules (microscopic level) but they can also stand for the number of moles of reactants or products. So the equation can also be read as 4 mol of iron react with 3 mol of oxygen to produce 2 mol ofiron(III) oxide. In addition, if we know the number of moles, the number of grams or molecules may be calculated. This is stoichiometry, the calculation of the amount (mass, moles, particles) of one substance in the chemical equation from another. The coefficients in the balanced chemical equation define the mathematical relationship between the reactants and products and allow the conversion from moles of one chemical species in the reaction to another. 

Andreeva, D. Tabakova, T Mitoy I. Andreev, A. (1991) Synthesis of a-Fe203 via oxidative hydrolysis ofiron(II) sulphate. J. Mat. Sci. Materials in Electronics 2 199-203... 

Diakonov, G.G. (1998) Thermodynamic properties ofiron oxides and hydroxides. II. Estimation of the surface and bulk thermodynamic properties of ordered and disordered arrangements (y-Fe203). Eur. J. Min. 10 17-29... 

Singh, B. Gilkes, R.J. (1992) Properties and distribution ofiron oxides and their assodation with minor elements in the soils of southwestern Australia. J. Soil Sd. 43 77-98... 

T. Akrmoto, S. (1984) Mossbauer study on the high pressure phase ofiron(III) oxide. Solid State Commun. 50 97—100 Szczypa, J. Matysiak, J. Kosmilski, M. (1994) Standard enthalpies of proton adsorption on hematite in various solvent systems. Abstracts of 8 Int. Conf. Colloid Surf. Chem. Adelaide... 

Torrent, J. Barron, V. (2000) Key role of phosphorus in the formation of the iron oxides in Mars soils Icarus 145 645-647 Torrent, J. Cabedo, A. (1986) Sources ofiron oxides in reddish brown soil profiles from cal-carenites in southern Spain. Geoderma 37 57-66... 

Wang, M.K Hsu, P.H. (1980) Effects of temperature and iron(III) concentration on the hydrolytic formation ofiron(III) oxyhydrox-ides and oxides. Soil Sd. Soc. Am. J. 44 ... 

Electronic promoters, for example, the alkali oxides, enhance the specific activity ofiron-alnmina catalysts. However, they rednce the inner snrface or lower the thermal stability and the resistance to oxygen-containing catalyst poisons. Promoter oxides that are rednced to the metal during the activation process, and form an alloy with the iron, are a special group in which cobalt is an example that is in industrial use. Oxygen-containing compounds such as H2O, CO, CO2, and O2 only temporarily poison the iron catalysts in low concentrations. Sulfur, phosphorus, arsenic, and chlorine compounds poison the catalyst permanently. 

Lesnefsky, E.J. Tissue iron overload and mechanisms ofiron-catalyzed oxidative injury. In Free Radicals in Diagnostic Medicine. A Systems Approach to Laboratory Technology, Clinical Correlations, and Antioxidant Therapy, Advances in Experimental Medicine and Biology Armstrong, D., Ed. Plenum Press New York, 1994 366, 129-146. 

Metallic iron is most often extracted from hematite ore, which consists ofiron(lll) oxide mixed with impurities such as silicon dioxide, Si02. 

Metal oxides usually consist of bulk oxides. As semiconductors, metal oxides catalyze the same kind of reactions as metals but in processes requiring higher temperatures. Often a mixture of various oxides is applied to increase the catalytic activity. For example, transition metals, such as M0O3 and Cr203, are good catalysts for polymerization of olefins a mixture of copper and chromium oxides, named copper chromite, is used for hydrogenation and a mixture ofiron and molybdenum oxide (ie, iron molybdate), is used for formaldehyde formation from methanol. 

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