$CaCO_{3}(S)\xrightarrow{Heat} CaO(S)+CO_{2}(g)$
Above reaction is an example of:

Question

$CaCO_{3}(S)\xrightarrow{Heat} CaO(S)+CO_{2}(g)$ 
Above reaction is an example of:

Accepted Answer

The correct option is (3):

The given reaction is $\mathrm{CaCO_{3}(S)\xrightarrow{Heat} CaO(S)+CO_{2}(g)}$. This reaction represents the breakdown of a single compound, calcium carbonate ($\mathrm{CaCO_3}$), into two simpler substances, calcium oxide ($\mathrm{CaO}$) and carbon dioxide ($\mathrm{CO_2}$), upon heating. In chemistry, a reaction where a single reactant breaks down into two or more products, usually with the input of energy (like heat, light, or electricity), is defined as a decomposition reaction. Thermal decomposition, specifically, is when heat is the energy source. Calcium carbonate's decomposition is a classic example of this, widely used in the production of lime ($\mathrm{CaO}$) in industries. Therefore, based on the definition of chemical reactions, this process fits perfectly into the category of a decomposition reaction.

The incorrect option is (1): Combination reaction.
A combination reaction involves two or more reactants combining to form a single product. For example, $\mathrm{A + B \rightarrow AB}$. This is the opposite of the given reaction where one reactant breaks into multiple products.

The incorrect option is (2): Double displacement reaction.
A double displacement reaction typically involves an exchange of ions between two compounds to form two new compounds. For example, $\mathrm{AB + CD \rightarrow AD + CB}$. The given reaction does not show an exchange of ions between two different compounds.

The incorrect option is (4): Displacement reaction.
A displacement reaction, also known as a single displacement reaction, occurs when one element reacts with a compound and displaces another element from that compound. For example, $\mathrm{A + BC \rightarrow AC + B}$. The given reaction involves a single compound breaking down, not an element displacing another from a compound.