Question

Define a precipitation reaction. Give its example and also express the reaction that occurs in the form of a balanced chemical equation.

Hint:

Precipitation reactions are important in many processes like water purification and qualitative analysis.

Answer 1

A precipitation reaction occurs when two soluble salts in aqueous solution react to form an insoluble solid, called a precipitate. 
Example: When silver nitrate reacts with sodium chloride, a white precipitate of silver chloride is formed: \[ {AgNO}_3 \, ({aq}) + {NaCl} \, ({aq}) \rightarrow {AgCl} \, ({s}) + {NaNO}_3 \, ({aq}) \] In this reaction, silver chloride (AgCl) is the precipitate.