Explain the given reactions with examples:
$(a)$ Saponification reaction
$(b)$ Combustion reaction

(N/A) Saponification: It is the process of making soap by the alkaline hydrolysis of an ester. When an ester like ethyl acetate reacts with sodium hydroxide, it produces sodium acetate and ethanol.
$CH_{3}COOC_{2}H_{5} + NaOH \rightarrow CH_{3}COONa + C_{2}H_{5}OH$
$(b)$ Combustion: It is the process of burning a carbon compound in the presence of oxygen to release energy in the form of heat and light. For example, the combustion of methane:
$CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O + \text{Heat and Light}$