Iron (II) oxide
|__ Fe 2+ __ O 2−|
|Surname||Iron (II) oxide|
|External identifiers / databases|
|Molar mass||71.85 g mol −1|
5.75 g cm −3
1369 ° C
almost insoluble in water
1.5 mg m −3
|As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .|
Iron (II) oxide (formerly also called iron oxide ) is a chemical compound of iron and oxygen and is one of the oxides . Iron (II) oxide is normally not built up stoichiometrically , the composition is around Fe 0.84 O to Fe 0.95 O. The reason for this is the similar crystal structure of iron (III) oxide and that crystal defects are entropically favorable.
Iron (II) oxide occurs during the fresh process / LD process (lowering the carbon content ) in steel production . Here, oxygen is blown into the iron melt. The oxygen combines with iron to form FeO, which in turn acts as an oxidizing agent for interfering foreign elements such as silicon , manganese and phosphorus :
With the help of calcium oxide (CaO) these oxides can be separated from the iron melt.
Extraction and presentation
Iron (II) oxide is formed during the reduction of iron (III) oxide with hydrogen or carbon monoxide . Iron (II) oxide can also be obtained by oxidizing iron under low oxygen pressure or with water vapor at temperatures above 560 ° C.
Furthermore, stoichiometric iron (II) oxide is formed in the reaction of Fe 1-x O and iron at 770 ° C. and 50 kbar oxygen pressure.
Iron (II) oxide is only stable above 560 ° C. Below this temperature down to approx. 300 ° C it tends to disproportionate to iron and iron (II, III) oxide :
- Entry on CI 77489 in the CosIng database of the EU Commission, accessed on February 26, 2020.
- Data sheet Iron (II) oxide at Sigma-Aldrich , accessed on March 29, 2011 ( PDF ).
- A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1652.
- Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 .