Iron(II) oxide

[5] FeO can be prepared by the thermal decomposition of iron(II) oxalate.

The procedure is conducted under an inert atmosphere to avoid the formation of iron(III) oxide (Fe2O3).

[6][7] Stoichiometric FeO can be prepared by heating Fe0.95O with metallic iron at 770 °C and 36 kbar.

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.

[8][10] Iron(II) oxide makes up approximately 9% of the Earth's mantle.

Iron(II) oxide
Iron(II) oxide
NFPA 704 four-colored diamond Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentine Flammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oil Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen Special hazards (white): no code