Question

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

Answer 1

A reaction in which an insoluble solid (called precipitate) is formed is called a precipitation reaction.

For example:
Na2CO3(aq) + CaCl2(aq) $→$ CaCO3(s) + 2NaCl(aq)
(Sodium carbonate) (Calcium chloride) (Calcium carbonate ) (Sodium chloride)
In this reaction, calcium carbonate is obtained as a precipitate. Hence, it is a precipitation reaction.

Another example of precipitation reaction is:
Na2SO4(aq) + BaCl2(aq) $→$ BaSO4(s) + 2NaCl(aq)
(Sodium sulphate) (Barium chloride) (Barium sulphate) (Sodium Chloride)
In this reaction, barium sulphate is obtained as a precipitate.