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Iron(III) oxide is a product of the oxidation of iron. It can be prepared in the laboratory by electrolyzing a solution of sodium bicarbonate, an inert electrolyte, with an iron anode: 4 Fe + 3 O 2 + 2 H 2 O → 4 FeO(OH) The resulting hydrated iron(III) oxide, written here as FeO(OH), dehydrates around 200 °C. [18] [19] 2 FeO(OH) → Fe 2 O 3 ...
Electrochemically oxidized iron (rust) An iron oxide is a chemical compound composed of iron and oxygen. ... Iron oxide pigment. The brown color indicates that iron ...
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe 3 O 4.It occurs in nature as the mineral magnetite.It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe 2 O 3) which also occurs naturally as the mineral hematite.
Iron forms various oxide and hydroxide compounds; the most common are iron(II,III) oxide (Fe 3 O 4), and iron(III) oxide (Fe 2 O 3). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. [12] These oxides are the principal ores ...
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 2+ Fe 3+ 2 O 4. It is one of the oxides of iron , and is ferrimagnetic ; [ 6 ] it is attracted to a magnet and can be magnetized to become a permanent magnet itself.
Elemental iron is virtually absent on the Earth's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths.Although iron is the fourth most abundant element in Earth's crust, composing about 5% by weight, [4] the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive ...
Goethite is an iron oxyhydroxide containing ferric iron. It is the main component of rust and bog iron ore. Goethite's hardness ranges from 5.0 to 5.5 on the Mohs Scale, and its specific gravity varies from 3.3 to 4.3. The mineral forms prismatic needle-like crystals ("needle ironstone" [3]) but is more typically massive. [2]
Hematite is not only harder than pure iron, but also much more brittle. The term kidney ore may be broadly used to describe botryoidal, mammillary, or reniform hematite. [8] Maghemite is a polymorph of hematite (γ-Fe 2 O 3) with the same chemical formula, but with a spinel structure like magnetite.