The chemical reaction in which an atom or group of atoms in the molecule is replaced by another atom or a group of atoms is called displacement reaction.

It is of two types:

• Single Displacement, Example: When zinc reacts with copper sulphate solution, copper is obtained along with the solution of zinc sulphate.

       \(\rm Zn\)+\(\rm CuSO_{4}\) → \(\rm ZnSO_{4}\)+\(\rm Cu\)

• Double Displacement, Example: When a solution of calcium chloride is treated with a solution of silver nitrate, calcium nitrate and silver chloride are formed.

\(\rm CaCl_{2}\)+\(\rm 2AgNO_{3}\) → \(\rm Ca(NO_{3})_{2}\)+ \(\rm 2AgCl\)