↪ In any chemical reaction oxidation and reduction always occur together.
↪ No oxidation is possible without reduction and vice versa.
↪ If electrons are lost by some chemical species in a reaction then there must be some other chemical species in the reaction which gains the same number of electrons.
↪ Hence, it is clear that oxidation and reduction are simultaneous chemical process. Reactions involving both oxidation and reduction are Redox reactions.



⁕ Oxidizing and Reducing Agent


↪ The substance which oxidizes other substances and itself reduces is called oxidizing agent or an oxidant.
↪ According to electronic concept an oxidizing agent is that substance (atom, molecule or ion) which causes oxidation to other by accepting one or more electrons.

↪ The substances which reduce other substances and themselves oxidize (undergoes oxidation) are called reducing agents or reductants.
↪ According to electronic concept a reducing agent is that substance (atom, molecule or ion) which causes reduction to other by losing one or more electrons.



In this reaction,

KBr is a reducing agent.
Cl₂ is an oxidizing agent.

Examples of some common oxidizing agents:
KMnO₄, K₂Cr₂O₇, HNO₃, Cl₂, MnO₄, Br₂, I₂, H₂SO₄, etc.

Examples of common reducing agents:
H₂O₂, Fe₂SO₄, H₂CO₃, H₂S, HI, Zn, H₂, etc.