Oxidation and Reduction Reaction

Development of oxidation and reduction reaction concept

1. Based on binding and releasing of oxygen

· Oxidation is a reaction in which an element or compound binds a number of oxygen.

Example: rusting of iron reaction

Oxidant is a substance which is a source of oxygen.

· Reduction is a reaction in which an element or compound release a number of oxygen.

Example: reaction between copper (II) oxide and hydrogen gas

Reductant is a substance which binds a number of oxygen.

2. Based on binding and releasing of electron

· Oxidation is a process of releasing a number of electrons.

Example:

· Reduction is a process of binding a number of electrons.

Example:

Oxidant is a substance which bind electron.

Reductant is a substance which release electron.

Basically, the process of oxidation and reduction reaction is happened simultaneously, which called redox reaction. Pay attention the redox reaction in the following process of sodium chloride formation.

3. Based on increasing and decreasing of oxidation number

· Oxidation is a chemical reaction in which happens increasing of oxidation number.

· Reduction is a chemical reaction in which happens decreasing of oxidation number.

Example:

In the reaction above, Na is a reductant because it undergoes the increase of oxidation number from 0 to +1. Cl₂ is an oxidant because it undergoes the decrease of oxidation number from 0 to -1.

Autoredox Reaction (Disproportionation Reaction)

Autoredox reaction is a chemical reaction in which a substance undergoes both oxidation and reduction, and acts as both oxidant and reductant result the dissimilar substances.

On the above reaction is a autoredox reaction, because Cl₂ undergoes both oxidation and reduction, and acts as both oxidant and reductant.