|Other names|| ferrous oxide|
|Molar mass||71.85 g/mol|
1370 °C (1643.15 K)
3414 °C (3687.15 K)
|Solubility in water||Insoluble|
| Except where noted otherwise, data are given for|
materials in their standard state
(at 25 °C, 100 kPa)
Iron(II) oxide, also known as ferrous oxide or ferrous iron, is one of the iron oxides. It is a black-colored powder with the chemical formula FeO. It consists of the chemical element iron in the oxidation state of 2 bonded to oxygen. Its mineral form is known as wüstite. Iron(II) oxide should not be confused with rust, which usually consists of hydrated iron(III) oxide (ferric oxide). Iron(II) oxide is an example of a non-stoichiometric compound and the ratio of the elements iron and oxygen can vary, samples are typically iron deficient with a compositions ranging from Fe0.84O to Fe0.95O.
- FeC2O4 → FeO + CO + CO2
The black powder can be made less reactive by heating. The heated sample is quenched to prevent disproportionation. Stoichiometric FeO can be prepared by heating Fe0.95O with metallic iron at 770°C and 36kbar.
- 4FeO → Fe + Fe3O4
Iron (II) oxide adopts the cubic, rock salt structure, where iron atoms are octahedrally coordinated by oxygen atoms and the oxygen atoms octahedrally coordinated by iron atoms. The non-stoichiometry occurs because of the ease of oxidation of FeII to FeIII effectively replacing a small portion of FeII with two thirds their number of FeIII, which take up tetrahedral positions in the close packed oxide lattice.
- ↑ 1,0 1,1 1,2 Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd Edition ed.). Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
- ↑ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999). Advanced Inorganic Chemistry (6th Edn.) New York:Wiley-Interscience. ISBN 0-471-19957-5.
- ↑ 3,0 3,1 3,2 Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford University Press ISBN 0198553706