Question

Explain exothermic reaction with the help of an example.

Answer 1

• Exothermic reaction - Chemical reactions in which heat energy is evolved are called exothermic reactions.
• Example - When water is added to quicklime$\left(\mathrm{CaO}\right)$ (calcium oxide), a lot of heat energy is produced along with calcium hydroxide$\left[\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$.

$\underset{\mathrm{Calcium}\mathrm{oxide}}{\mathrm{CaO}}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}\to \underset{\mathrm{Calcium}\mathrm{hydroxide}}{\mathrm{Ca}{\left(\mathrm{OH}\right)}_2}+\mathrm{Heat}$