Types of Chemical reactions
In this part, we will study the different types of chemical reactions.
These reactions help us to understand how substances change during a chemical reaction.
All explanations are given in very simple language for easy understanding.
1.Combination Reaction
A chemical reaction in which two or more substances combine to form a single product is called a Combination Reaction. Example : Calcium oxide + Water → Calcium hydroxide
CaO + H₂O → Ca(OH)₂
2.Decomposition Reaction
A chemical reaction in which a single compound breaks down into two or more simpler substances is called a decomposition reaction.
Example: Calcium carbonate → Calcium oxide + Carbon dioxide
CaCO₃ → CaO + CO₂
3.Displacement Reaction
A chemical reaction in which a more reactive element displaces a less reactive element from its compound is called a displacement reaction.
Example : Iron + Copper sulphate → Iron sulphate + Copper
Fe + CuSO₄ → FeSO₄ + Cu
4.Double Displacement Reaction
A chemical reaction in which two compounds exchange their ions to form two new compounds is called a double displacement reaction.
Example : Sodium sulphate + Barium chloride → Barium sulphate + Sodium chloride
Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl
5.Oxidation Reaction
A chemical reaction in which a substance gains oxygen or loses hydrogen is called an oxidation reaction.
Example : Copper + Oxygen → Copper oxide
2Cu + O₂ → 2CuO
6.Reduction Reaction
A chemical reaction in which a substance loses oxygen or gains hydrogen is called a reduction reaction.
Example : Copper oxide + Hydrogen → Copper + Water
CuO + H₂ → Cu + H₂O
7.Oxidation and Reduction occur together
Oxidation and reduction always take place together in a chemical reaction. Such reactions are called redox reactions.
Example : Example:
CuO + H₂ → Cu + H₂O
Example:
CuO + H₂ → Cu + H₂O
- Oxidation:
Hydrogen gains oxygen to form water (H₂O).
Therefore, hydrogen is oxidised. - Reduction:
Copper oxide loses oxygen to form copper (Cu).
Therefore, copper oxide is reduced.
Conclusion:
Oxidation and reduction always occur together in a chemical reaction.
Such reactions are called redox reactions.