Question

What do you mean by exothermic reaction?

Answer 1

Exothermic reaction - A reaction that takes place with the release of heat along with the formation of a product is known as an exothermic reaction.

Representation - Reactants $\to$Products + Q Kcal (or)

Reactant - Q Kcal $\to$ Products

Q = Heat energy released

Example

$$\begin{gathered} \mathrm{C}+{\mathrm{O}}_2\to {\mathrm{CO}}_2+94\mathrm{Kcal} \\ \mathrm{carbon}\mathrm{oxygen}\mathrm{carbon}\mathrm{dioxide}\mathrm{energy} \end{gathered}$$

• For the formation of CO₂ from carbon and oxygen, the bonds between oxygen atoms in oxygen molecules should be broken.
• For the breaking of this bond, some amount of energy is absorbed.
• At the same time, some amount of energy is released during the formation of new bonds between carbon and oxygen.
• If the energy released is more than the energy required during the reaction, the difference in energy is released as heat energy.
• This type of reaction is known as an exothermic reaction.