Question

Define the term decomposition reaction. Give one example of each of thermal decomposition and electrolytic decomposition.

Answer 1

Hint: We know that there are different types of chemical reactions. Examples of chemical reactions are combination reactions, redox reactions, combustion reactions, displacement reactions and decomposition reactions. We know that combination reactions are those reactions where two reactants are combined to form one product. The reverse of combination reactions are decomposition reactions.

Complete answer:
We can define decomposition reactions as chemical reactions where two products (or) more than two products are obtained when one reactant gets broken down. We can write the general equation for decomposition reaction as,
$AB \to A + B$
Here, we can say AB indicates the parent molecule which is the reactant and the product molecules are A and B.
One of the best examples of decomposition reaction is decomposition of carbonic acid that is found in soft drinks. We can obtain water and carbon dioxide as products during decomposition of carbonic acid.
${H_2}C{O_3} \to {H_2}O + C{O_2}$
A thermal decomposition reaction can be characterized as a disintegration reaction which is actuated by thermal energy. In better words, a thermal decomposition reaction expects energy to be provided to the reactants in a state of heat. Such reactions are by and large endothermic since energy is needed to break the substance and separate the constituent components. A typical illustration of a thermal decomposition reaction is given beneath.
$CaC{O_3} \to CaO + C{O_2}$
When warmed, calcium carbonate disintegrates into calcium oxide and carbon dioxide. This interaction is utilized in the preparation of quick lime, which is a significant substance in several industries.
An electrolytic decomposition reaction is a kind of decomposition reaction wherein the actuation energy for decomposition is given as electrical energy. An illustration of an electrolytic decomposition reaction is the electrolysis of water, which can be addressed by the chemical equation as:
$2{H_2}O \to 2{H_2} + {O_2}$

Note:
One could easily remember combination reaction and decomposition reaction. In combination reaction, two reactants form one product and in decomposition reaction, one reactant forms two products. In daily use, decomposition reactions are used in thermite welding, relief from indigestion of acid, and formation of calcium oxide (or) cement.