OXIDATION

Addition of Oxygen or any other electronegative element.

E.g., 2Mg + O2 → 2MgO

Removal of Hydrogen
e.g., H2S + Cl2 → 2HCl + S

Increase in positive charge
e.g., Fe2+→ Fe3+ + e -

Increase in oxidation number

(+2) (+4)
E.g., SnCl₂→ SnCl4

Removal of electron
e.g. Sn2 + → Sn4+ + 2e-

REDUCTION

Removal of Oxygen or any other electronegative element.
E.g., CuO + C → Cu + CO

Addition of Hydrogen
e.g. S + H2 → H2S

Decrease in positive charge
e.g. Fe3+ +e - Fe2+

Decrease in oxidation number

(+7) (+2)
E.g., MnO4 → Mn2+

Addition of electron
e.g. Fe3 + + e- → Fe2+

REDOX REACTION

The reaction in which oxidation and reduction take place simultaneously is defined as redox reaction