What do you mean by a precipitation reaction? Explain by giving examples.

(N/A) reaction in which an insoluble solid (called precipitate) is formed is called a precipitation reaction.
For example:
$Na_2CO_{3(aq)} + CaCl_{2(aq)} \to CaCO_{3(s)} + 2NaCl_{(aq)}$
In this reaction,calcium carbonate $(CaCO_3)$ is obtained as a white precipitate.
Another example of a precipitation reaction is:
$Na_2SO_{4(aq)} + BaCl_{2(aq)} \to BaSO_{4(s)} + 2NaCl_{(aq)}$
In this reaction,barium sulphate $(BaSO_4)$ is obtained as a white precipitate.