Appearance | lustrous metallic with a grayish tinge |
Standard atomic weight A(Fe) | 55.845(2)[1] |
Atomic number (Z) | 26 |
Group | group 8 |
Period | period 4 |
Block | d-block |
Element category | transition metal |
Electron configuration | [Ar] 3d6 4s2 |
Electrons per shell | 2, 8, 14, 2 |
Iron has an atomic number 26 with an element symbol Fe (Ferrum) and it’s the first metal of the transition series.Not only Iron can be easily found on the earth core and the surface of it but also it is the most common metal on the earth surface. In addition, from all the other metal from the list, Iron is the fourth common element found on the earth surface.
Like the other groups 8 elements, ruthenium and osmium, iron exists to have in a wide range of oxidation states, −2 to +7, although +2 and +3 are the more common. Elemental iron occurs in shooting stars and other less oxygen environments, but it gets charged up with oxygen and water. Fresh iron surfaces appear shinny silvery-gray but oxidize in standard air environment to give hydrated iron oxides, most commonly known as rust. Unlike the metals that form passivity oxide layers, iron oxides occupy supplementary volume than the metal and thus flake off, exposing fresh surfaces production for corrosion.
Industrial routes
For a limited method when it is needed, pure iron is produced in the laboratory in less quantities by reducing the amount of pure oxide or hydroxide with hydrogen or forming iron pent carbonyl and heating it to 250 °C so that it decomposes to form pure iron powder. Other method is electrolysis of ferrous chloride onto an iron cathode
Blast furnace processing
In the furnace, the coke reacts with O2 in the air blast to create CO (Carbon monoxide):
2 C + O2 → 2 CO
The carbon monoxide reduces the iron ore (in the chemical equation below, hematite) to molten iron, transforming to carbon dioxide in the process:
Fe2O3 + 3 CO → 2 Fe + 3 CO2
2 Fe2O3 + 3 C → 4 Fe + 3 CO2
CaCO3 → CaO + CO2
CaO + SiO2 → CaSiO3
Direct iron reduction
Two major reactions contain the direct reduction process:
2 CH4 + O2 → 2 CO + 4 H2
Fe2O3 + CO + 2 H2 → 2 Fe + CO2 + 2 H2O
Silica is discarded by adding a limestone flux as described above.
Characteristics
Physical properties | |
Phase at STP | solid |
Melting point | 1811 K (1538 °C, 2800 °F) |
Boiling point | 3134 K (2862 °C, 5182 °F) |
Density (near r.t.) | 7.874 g/cm3 |
when liquid (at m.p.) | 6.98 g/cm3 |
Heat of fusion | 13.81 kJ/mol |
Heat of vaporization | 340 kJ/mol |
Molar heat capacity | 25.10 J/(mol·K) |
Vapor pressure |
Mechanical properties
Chemistry and compound
It forms compounds mainly in the +2 and +3 oxidation states. Usually, iron (II) compounds called ferrous, and iron(III) compounds ferric. It also occurs in top oxidation states, e.g. the purple potassium ferrate (K2FeO4), which has iron in its +6-oxidation state. Although iron(VIII) oxide (FeO4) has been claimed, the result could not be produced again and such a species (at least with iron in its +8-oxidation state) has been found to be unlikely computationally. But, one form of anionic [FeO4]– with iron in its +7-oxidation state, along with an iron(V)-peroxo isomer, has been found by infrared spectroscopy at 4 K after co condensation of laser-ablated Fe atoms with a mixture of O2/Ar.Iron (IV) is a general intermediate in many biochemical oxidation reactions. Numerousorgano iron compounds have formal oxidation states of +1, 0, −1, or even −2. The oxidation states and other bonding properties are often studied using the technique of Mössbauer spectroscopy.Many mixed valence compounds contain togetheriron (II) and iron (III) centers, such as magnetite and Prussian blue (Fe4(Fe [CN]6)3).The last is used as the traditional “blue” in blueprints.
Iron stands first of the transition metals that isunable to reach its group oxidation state of +8, although its heavier congener’s ruthenium and osmium can, with ruthenium having more difficulty than osmium. Ruthenium exhibits an aqueous cationic chemistry in its low-down oxidation states parallel to that of iron, but osmium does not, favoring high oxidation states in which it forms anionic complexes. In the other half of the 3d transition series, vertical similarities least on the groups compete with the horizontal similarities of iron with its neighbor’s cobalt and nickel in the periodic table, which are ferromagnetic at room temperature and contribute to similar chemistry. As such, iron, cobalt, and nickel are sometimes combined as the iron triad.
Applications
The following are the application areas of iron: