Manganese

Today I´m going to talk about manganese

 

Manganese metal is gray-white, resembling iron, but is harder and very brittle. The metal is reactive chemically, and decomposes cold water slowly. Manganese is widely distributed throughout the animal kingdom. It is an important trace element and may be essential for utilisation of vitamin B. Manganese is present in quantity the floor of oceans. It is an important component of steel.

Table: basic information about and classifications of manganese.

Name: Manganese Symbol: Mn Atomic number: 25 Atomic weight: 54.938045 (5) Standard state: solid at 298 K CAS Registry ID: 7439-96-5

Group in periodic table: 7 Group name: (none) Period in periodic table: 4 Block in periodic table: d-block Colour: silvery metallic Classification: Metallic

Manganese: historical information

Manganese was discovered by Johann Gahn at 1774 in Sweden. Origin of name: from the Latin word "magnes" meaning "magnet", or "magnesia nigri" meaning "black magnesia" (MnO₂).

                             

 

 

 

Manganese metal was isolated by Gahn in 1774. He reduced the dioxide (MnO₂, as the mineral pyrolusite) with charcoal (essentially carbon) by heating and the result was a sample of the metal manganese.

Manganese: physical properties

• Melting point: 1519 [or 1246 °C (2275 °F)] K
• Boiling poin: 2334 [or 2061 °C (3742 °F)] K
• Density of solid: 7470 kg m^-3

 

Manganese: orbital properties

• Ground state electron configuration:  [Ar].3d⁵.4s²
• Shell structure:  2.8.13.2
• Term symbol:   ⁶S_5/2
• Pauling electronegativity: 1.55 (Pauling units)
•  First ionisation energy: 717.3 kJ mol^-1
•  Second ionisation energy: 1509.0 kJ mol^-1

 

Isolation

Isolation: it is not normally necessary to make manganese in the laboratory as it is available commercially. Nearly all manganese produced commercially is used in the steel industry as ferromanganese. This made by the reduction of iron oxide, Fe₂O₃, and managanese dioxide, MnO₂, in appropriate proportions with carbon (as coke) in a blast furnace. Pure manganese is available through the electrolysis of manganese sulphate, MnSO₄,