What are the various types of chemical reaction? Explain.

The various types of chemical reactions are:

i. Addition reactions:

The reaction in which two or more reactants combine to form a single product are known as addition reaction. In this new type of bonds are formed between the reactants.

Ex- C(s) + O₂(g) → CO₂(g)

ii. Replacement reactions:

In these reactions a more reactive element replaces a less reactive element from its compound.

Ex- Fe + CuSO₄→ FeSO₄→ FeSO₄ + Cu

Double displacement reaction:

This is a subcategory of replacement reactions in which mutual exchange of ions occurs between two reactants.

Ex – CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄

iii. Dissociation reactions:

These are the reactions in which a single reactant decompose to form two or more products. There are various types of dissociation reaction as follows: -

The types of dissociation reaction are :-

a) Electrolysis:

In this method electrical energy is used to decompose the reactant into products. Electric energy is passes through the fused salt of the substance.

Example – Electrolysis of water gives hydrogen and oxygen as shown –

2H₂O 2H₂ + O₂

b) Thermal decomposition:

In this method heat energy is used to decompose the reactant into products.

Example – Decomposition of calcium carbonate as shown to give calcium oxide and oxygen–

CaCO₃ CaO + O₂

c) Photolysis:

In this method energy from the sun is used to decompose the reactant into products.

Example – Decomposition of hydrogen bromide s shown –

2HBr → H₂ + Br₂

iv. Reversible reactions:

The reactions those which occur in both forward and backward direction are known as reversible reactions.

Ex- N₂ + 3H₂⇌ 2NH₃

v. Irreversible reactions:

Those reactions which flow in only one direction and products are formed from the reactants are known as irreversible reactions.

Ex- C + O₂→ CO₂