What is Reduction

Reduction

According to the old (classical) concept, it is defined as the process which involves the addition of hydrogen or any other electro-positive element or radical to an element or a compound or the removal of oxygen or any other electro­negative element or radical from a compound.

For example:

Addition of Hydrogen or any other electro-positive element.

• N₂ +3H₂ –> 2NH₃

In this reaction H₂ is added to N₂ and is reduced to NH₃.

• HgCl₂ + Hg –> Hg₂Cl₂

Here, Hg (mercury), an electro-positive element, is added to HgCl₂ and is thus reduced to Hg₂Cl₂.

Removal of oxygen or any other electro-negative element or radical.

• 2HgO –> 2Hg +O₂

Here, HgO looses O₂ and is reduced to Hg.

• 2FeCl₃ + H₂ –> 2FeCl₂ + 2HCI

Here, FeCl₃ looses Cl₂, an electro-negative element and is reduced to FeCl₂.

According to the electronic concept, reduction is a process which involves gain of electron by an atom. Due to gaining of electron there will be an increase of negative charge or decrease in positive charge.

Example:

• 2Na + Cl₂ –> 2NaCl

In the above reaction chlorine gains one electron and is thus reduced.