Explain the different types of double decomposition reactions by giving suitable equations.

Different types of double decomposition reactions are:

1. Precipitation reaction — A reaction between two compounds in aqueous solution state to give two new compounds one of which is insoluble (precipitate) is called a Precipitation reaction.
   For example, when H₂S is passed through copper sulphate solution, a black precipitate of copper sulphide is obtained.
   CuSO₄ (aq) + H₂S (g) ⟶ CuS [black ppt.] ↓ + H₂SO₄

2. Neutralization reaction — The reaction between an acid and a base that forms salt and water only is referred to as Neutralization reaction.
   For example, Sodium chloride (base) reacts with HCl (acid) to form salt and water only.
   NaOH + HCl ⟶ NaCl + H₂O