Oxidation is the loss of electrons, while reduction is the gain of electrons. The atom that loses electrons is the oxidizing agent, and the atom that gains electrons is the reducing agent. For example, in the reaction Mg + Cl2 → MgCl2, magnesium (Mg) is oxidized as it loses electrons and becomes Mg2+, while chlorine (Cl) is reduced as it gains electrons and becomes Cl-. Magnesium serves as the reducing agent and chlorine serves as the oxidizing agent.

1. OXIDATION AND REDUCTION
Oxidation is the process of loss of electrons .
Reduction is the process of gain of electrons .
The atom which loses electrons are called
reducing agents
The atoms which gain electrons are called
oxidising agents.

4. MgCl2
• Electronic configuration of Mg
• 2,8,2
• Mg0 - 2 e- → Mg 2+(oxidation)
• Electronic configuration of Cl
• 2,8,7
• 2 Cl0 + 2 e- → 2 Cl-I (reduction)
Cl
2 e
Cl
e
e
Mg

6. Mg + F2 MgF2
Oxidised atom Magnesium
Equation of oxidation Mg Mg2+ + 2e
Reduced atom Flourine
Equation of reduction F + 1 e F1 -
Oxidising agent F
Reducing agent Mg

7. Oxidation number
• Oxidation number, also called oxidation state,
is the total number of electrons that an atom
either gains or loses in order to form
a chemical bond with another atom.
•

8. 2Na +C l2 2NaCl
Oxidised atom Na
Equation Na Na + + 1e
Reduced atom Cl
Equation Cl + 1e Cl--
Reducing agent Na
Oxidising agent Cl