Question: What do you mean by a precipitation reaction? Explain by giving examples.
Answer:
A reaction in which an insoluble solid (called precipitate) is formed is called a precipitation reaction.
For example:
NaCO₃(aq) + CaCl₂(aq) ⟶ CaCO₃(s) + 2NaCl(aq)
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) + NaCl(aq)
In this reaction, barium sulphate is obtained as a precipitate.