Explain Displacement reaction with examples.

Hint: Displacement reactions is a chemical reaction in which one reactant present in the equation is displaced with the other reactant and owing to this phenomenon this reaction is also called the replacement reaction.

Complete step by step answer:
So let’s start our discussion with understanding the basic definition of the displacement reactions then we will proceed further to understand the type of displacement reactions with some examples.
Displacement reaction is a chemical reaction in which one reactant present in the equation is displaced with the other reactant and owing to this phenomenon this reaction is also called the replacement reaction.
The reason behind it being called a replacement type of reaction is the replacement of one reactant’s ion by the other reactant’s ion.
Let us take an example
\[{\text{A + BC }} \to {\text{ AC + B}}\]
Here the initial reactant was \[{\text{A}}\] and \[{\text{B - C}}\], now as we move to the product side we observe that an ion has removed \[{\text{B}}\] from the compound \[{\text{B - C}}\].
This action showed by the \[{\text{A}}\] ion is due to its high reactivity as compared to the \[{\text{B}}\] ion in the compound and thus ultimately replacement or displacement reaction takes place.
Displacement reaction is classified into 2 categories-
Single displacement reaction- as the name says, this reaction involves the replacement of one element from the salt or compound of the other. Generally only one reactant undergoes the displacement process and replaces the ion in another reactant.
Ex-\[\;{\text{A + BC }} \to {\text{ AC + B}}\]
Double displacement reaction-this type of reaction involves the replacement of both reactant’s ion with each other that is 2 reactants undergo the displacement.
Ex- \[{\text{AB + CD}} \to {\text{AC + BD}}\]

Note:
Displacement reactions are used in many places and are of great importance to industry. Some of the widely known uses of displacement reaction are thermal welding, steel making, and extraction of metal and relief from acid indigestion.