Question

Differentiate between exothermic and endothermic reactions.

Answer 1

Exothermic reaction

Endothermic reaction

The reaction in which heat energy is liberated to the surroundings is known as an exothermic reaction. There is an increase in the temperature during the reaction. Energy is released from the system. The extra energy is given out when the energy absorbed for breaking a bond is more than the energy released during the formation of a new bond. An example for the exothermic reaction: $\underset{\mathrm{nitrogen}}{{\mathrm{N}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{nitric}\mathrm{oxide}}{2\mathrm{NO}\left(\mathrm{g}\right)}+\mathrm{heat}$

The reaction in which heat energy is absorbed from the surroundings is known as an endothermic reaction. There is a decrease in the temperature during the reaction. Energy is given to the system. The energy is absorbed when the system needs more energy during the formation of a bond. $\underset{\mathrm{carbon}}{\mathrm{C}\left(\mathrm{g}\right)}+\underset{\mathrm{oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{heat}}{\to }\underset{\mathrm{carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$