The useful transition metal ─

Iron

Basic Information

Chemical Symbol :Fe atomic number 26 The fourth most common element in the earth

crust Oxidation states varies from -2 to +6 +2(green)

and +3(Yellow) are the most common Density (near r.t.) : 7.874 g·cm−3 Melting point :1538 °C  Boiling point : 2862 °C

Compound of iron

Iron forms compound mainly in +2 or +3 oxidation states Iron(III) compound called ferric and Iron(II) compound called ferrous e.g Fe(II) Sulphate or Fe(III)Sulphate

Iron(IV) is a common intermediate in many in biochemical oxidation reactions

Iron compound with +6 oxidation states Potassium Ferrate (K2FeO4)

The iron compounds produced on the largest scale in industry are iron(II) sulfate (FeSO4·7H2O) and iron(III) chloride (FeCl3). Iron(II) compounds tend to be oxidized to iron(III) compounds in the air.

Iron reacts with oxygen in the air to form various oxide and hydroxide compounds; the most common are iron(II,III) oxide (Fe3O4), and iron(III) oxide (Fe2O3).

Extraction of Iron

Heating metal ore with carbon(carbon reduction)

At high temperature, carbon can react with iron(III) oxide in haematite. In the process, carbon removes the oxygen from iron(III) oxide to form iron

Iron(II,III) oxides +carbon monoxide →iron+ carbon dioxide

Industrial Use

the most widely used metal in the world, in proportion 95% of metal production

Low Cost, High Strength. Important in construction and industrial use

Steel Iron with a certain proportion of carbon produce through smelting process, this

is to strengthened and hardened the pure iron, steel is 1000 times harder than pure iron.

Steel, low carbon iron alloys and alloy steel are commonly used in industry Iron(II,III) oxide (Fe3O4), and iron(III) oxide (Fe2O3) are used in the production

of ferrites, useful magnetic storage media in computers, and pigments. Iron is used for protection from ionizing radiation. Although it is lighter than

another traditional protection material, lead, it is much stronger mechanically.

Stainless steel

Biological use ranging from the evolutionarily primitive

archaea to humans ecessary trace element found in nearly all

living organisms Iron-containing enzymes and proteins, often

containing heme prosthetic groups mediate redox reactions, and of oxygen

carrier proteins such as hemoglobin, myoglobinand leghemoglobin

Disadvantage of iron

suffer badly from rust if not protected in some way

Painting, galvanization, passivation, plastic coating and bluing are all used to protect iron from rust