Question

What happens when silver nitrate solution is added to sodium chloride solution?
A. Write the equation for the reaction which takes place
B. Name the type of the reaction involved.

Answer 1

Hint: Classification of chemical reactions can be done on the basis of the number and type of reactants involved, the number and type of products produced and the specific chemical changes that accompany the evolution of heat or liberation of a gas.

Complete answer:
Silver nitrate is an ionic compound formed from the combination of silver cations and nitrate anions. Sodium chloride also known as common salt is also an ionic salt. The two solutions when mixed together result in a reaction in which the cations get exchanged and form new salts with the corresponding anions. Such a reaction involving exchange of cations to give new ionic compounds is known as a double displacement reaction in which both the metallic species displace each other from their solutions.
This reaction takes place as silver ions have more affinity for chloride ions and sodium ions have more affinity for nitrate ions. Thus, the products formed are silver chloride and sodium nitrate.
But both the new salts are not equally soluble in water, though silver nitrate was present as an aqueous solution but silver chloride immediately precipitates out as a white solid.
The chemical equation for the reaction can be written as follows:
\[NaCl(aq) + AgN{O_3}(aq) \to AgCl(s) \downarrow + NaN{O_3}(aq)\]
Hence, the reaction between sodium chloride and silver nitrate is a double displacement reaction in which silver chloride gets precipitated out in the form of a white solid.

Note:
 The arrow pointing downwards in the reaction indicates precipitation. The precipitate is formed as a result of low solubility of silver chloride compounds. The difference between the ionic sizes of silver and chloride ions and the lattice enthalpy being higher than the hydration enthalpy are the main reasons responsible for its low solubility.