Fe2O3 Full Form

What is full form of Fe2O3?

The inorganic chemical with the formula Fe2O3
\begin{equation}
Fe_{2}{}O_{3}
\end{equation}

is Iron (III) Oxide or Ferric Oxide. It is one of three major Iron oxides, the other two being Iron II Oxide (FeO) or also called Ferrous Oxide which is uncommon, and Iron III Oxide (Fe3O4) which occurs naturally as the mineral Magnetite.
Fe2O3 is often known as hematite as the primary source of Iron for the steel industry. Acids have a high affinity for Fe2O3. Iron(III) Oxide is commonly referred to as rust, and this name is appropriate to some extent because rust has certain features and has a comparable composition; nevertheless, in chemistry, rust is classified as Hydrous ferric oxide.

This Story also Contains

1. What is full form of Fe2O3?
2. Structure
3. Chemical Reactions
4. Preparations
5. Uses
6. Hydrated Iron (III) oxides

Structure

Fe2O3 is available in a variety of polymorphs. Iron uses octahedral coordination geometry in the primary one. In other words, each Fe centre is linked to six Oxygen ligands. Some of the Iron in the polymorph is tetrahedral, with four oxygen ligands.

Alpha Phase: The most prevalent form of α-Fe2O3 is the rhombohedral, corundum (α-Al2O3) structure. It naturally occurs as the mineral hematite, which is exploited as the primary Iron ore. It is antiferromagnetic below 260 K (Morin transition temperature) and ferromagnetic between 260 K and the Néel temperature, 950 K. It is simple to make, utilising both thermal breakdown and liquid-phase precipitation. Many variables influence its magnetic characteristics, including pressure, particle size, and magnetic field intensity.

The cubic structure of gamma phase γ-Fe2O3 At high temperatures, it metastable and converts from the alpha phase. It may be found in nature as the mineral maghemite. Although ultrafine particles smaller than 10 nanometers are superparamagnetic, they are ferromagnetic and used in recording tapes. It is made by thermally dehydrating gamma iron(III) oxide-hydroxide. Another way is to carefully oxidise Iron (II, III) Oxide (Fe3O4). The thermal breakdown of Iron (III) oxalate can be used to produce ultrafine particles.

Other phases: Several other stages have been discovered or claimed. The -phase is cubic, body-centred (space group Ia3), metastable, and transitions to the alpha phase at temperatures exceeding 500 °C (930 °F). It can be made via carbon reduction of hematite, pyrolysis of iron(III) chloride solution, or thermal breakdown of iron(III) sulphate.

The epsilon () phase is rhombic and has qualities that are midway between alpha and gamma. It may have magnetic properties that are helpful for applications such as high density recording mediums for huge data storage. The preparation of the pure epsilon phase has proven to be extremely difficult. The thermal transition of the gamma phase can produce material with a large fraction of the epsilon phase.

The epsilon phase is likewise metastable, changing to the alpha phase at temperatures ranging from 500 to 750 °C (930 to 1,380 °F). It may also be made by oxidising Iron in an electric arc or by precipitating iron(III) nitrate in a sol-gel. Epsilon Iron (III) Oxide has been discovered in ancient Chinese Jian pottery glazes, which may give insight into how to generate that form in the lab.

Furthermore, an amorphous form is claimed at high pressure.

Liquid Phase: Based on measurements of slightly oxygen deficient supercooled liquid Iron Oxide droplets, molten Fe2O3 is expected to have a coordination number of close to 5 oxygen atoms around each Iron atom, where supercooling avoids the need for the high oxygen pressures required above the melting point to maintain stoichiometry.

Chemical Reactions

The most important reaction is carbothermal reduction, which produces Iron for steel production:

\begin{equation}

Fe_{2}{}O_{3} + 3 CO \rightarrow 2 Fe + 3 CO_{2}

\end{equation}

The very exothermic thermite reaction with aluminium is another redox reaction.

\begin{equation}

2 Al + Fe_{2}{}O_{3} \rightarrow 2 Fe + Al_{2}O_{3}

\end{equation}

This method is used to weld thick metals, such as railroad track rails, by funnelling molten Iron in between two pieces of rail using a ceramic container. Thermite is also employed in the manufacture of weaponry as well as small-scale cast-Iron sculptures and tools. At about 400 °C, partial reduction with hydrogen produces magnetite, a black magnetic material containing both Fe(III) and Fe.

\begin{equation}

3 Fe_{2}{}O_{3} + H_{2} \rightarrow 2 Fe_{3}{}O_{4} + H_{2}O

\end{equation}

Iron(III) Oxide is insoluble in water but rapidly dissolves in strong acids such as hydrochloric and sulfuric acids. It also dissolves effectively in chelating agent solutions such as EDTA and oxalic acid. Heat Iron (III) oxides with other metal oxides or carbonates to produce ferrates (ferrate (III)):

\begin{equation}

ZnO + Fe_{2}{}O_{3} \rightarrow Zn(FeO_{2})2

\end{equation}

Preparations

Iron(III) Oxide is a byproduct of Iron oxidation. In the laboratory, it may be made by electrolyzing a solution of sodium bicarbonate, an innocuous electrolyte, with an Iron anode:

\begin{equation}

4 Fe + 3 O_{2} + 2 HO_{2}O \rightarrow 4 FeO(OH)

\end{equation}

Around 200 °C, the resulting hydrated iron(III) oxide, written here as FeO(OH), dehydrates.

\begin{equation}

2 FeO(OH) \rightarrow Fe_{2}O_{3} + H_{2}O

\end{equation}

Uses

1. The Iron industry: Iron(III) Oxide is primarily used as a feedstock in the steel and Iron industries, such as the manufacturing of iron, steel, and various alloys.

2. Polishing: The term "jeweller's rouge" "red rouge" or simply rouge refers to a fine powder of ferric oxide. It is used to polish metallic jewellery and glasses, as well as historically as a cosmetic. Rouge is slower to cut than certain current polishes, like cerium (IV) oxide, but it is still employed in optics manufacture and by jewellers due to the better quality it can provide. When polishing gold, the rouge slightly stains the gold, which contributes to the completed piece's look.

3. Rouge can be purchased as a powder, paste, laced on polishing cloths, or as a solid bar (with a wax or grease binder). Other polishing compounds, including those that do not include Iron oxide, are frequently referred to as "rouge" Jewellers use ultrasonic cleaning to remove leftover rouge from jewellery. Products marketed as "stropping compound" are frequently applied to a leather strop to aid in the formation of a razor edge on knives, straight razors, and other edged tools. Magnetic storage

4. The most common magnetic particle utilised in all forms of magnetic storage and recording medium, including magnetic discs (for data storage) and magnetic tape, was iron(III) Oxide (used in audio and both data storage and video recording).

Cobalt alloy replaced it in computer drives, allowing thinner magnetic films with increased storage density.

5. Photocatalysis

\begin{equation}

\alpha -Fe_{2}O_{3}

\end{equation}

as a photoanode for solar water oxidation has been investigated. However, the short diffusion length (2-4 nm) of photo-excited charge carriers and consequent quick recombination restrict its efficacy, necessitating a substantial overpotential to drive the reaction. The goal of research has been to improve the water oxidation performance of Fe2O3 by nanostructuring, surface functionalization, or the utilisation of other crystal phases such as β-Fe2O3 .

\begin{equation}

\beta -Fe_{2}O_{3}

\end{equation}

6. Medicine: Calamine lotion is mostly composed of zinc oxide, which acts as an astringent, and around 0.5% iron(III) oxide, the product's active component, which acts as an antipruritic. The pink colour of the lotion is primarily due to the red colour of iron(III) oxide.

Hydrated Iron (III) oxides

There are several Iron (III) Oxide hydrates. When alkali is added to soluble Fe(III) salt solutions, a red-brown gelatinous precipitate occurs. This is

\begin{equation}

Fe_{2}O_{3}\cdot H_{2}O

\end{equation}

(sometimes written as Fe(O)OH), not Fe(OH)3. There are several types of Fe(III) hydrated oxide. The red lepidocrocite (γ-Fe(O)OH) appears on the exterior of rusticles, whereas the orange goethite (α-Fe(O)OH) occurs within them. When

\begin{equation}

Fe_{2}O_{3}\cdot H_{2}O

\end{equation}

is heated, it loses its hydration. At 1670 K, further heating transforms Fe2O3 to black

\begin{equation}

Fe_{3}O_{4} (Fe^{II}Fe^{III}_{2}O_{4})

\end{equation}

, also known as mineral magnetite. In acids, Fe(O)OH dissolves, yielding

\begin{equation}

[Fe(H_{2}O)6]^{3+}

\end{equation}

. Fe2O3 generates

\begin{equation}

[Fe(OH)_{6}]^{3-}

\end{equation}

in concentrated aqueous alkali.