Question

Why are decomposition reactions called the opposite of combination reactions? Write equations for this reaction.

Answer 1

Combination reaction

• It is a type of reaction in which one or more reactants react together to produce new products.
• The general description of a combination reaction is as follows:-

$\text{X+Y→XY}$

Example of combination reaction

The chemical reaction is as follows:-

$\mathrm{CaO}\left(\mathrm{S}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)$

Decomposition reaction

• A reaction in which a compound breaks into two or simpler compounds is called a Decomposition Reaction.
• The general description of a decomposition reaction is as follows:-
• $\text{XY→X+Y}$

Example of decomposition reaction

From the above examples, it can be said that decomposition reactions are called the opposite of combination reactions.