Question

Give one example of an exothermic reaction and one of an endothermic reaction.

Answer 1

Exothermic reactions:

• The reactions in which energy is released in the form of light or heat when products are formed are called exothermic reactions.
• Exothermic reactions are favoured by low-temperature surroundings.
• Example: $\underset{\mathrm{Carbon}}{\mathrm{C}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Heat}}{∆}$

Endothermic reactions:

• The reactions in which heat energy is absorbed when products are formed are called endothermic reactions.
• Endothermic reactions are favoured by high -temperature surroundings
• Example: $\underset{\mathrm{Nitrogen}}{{\mathrm{N}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Heat}}{∆}\to \underset{\mathrm{Nitric}\mathrm{oxide}}{2\mathrm{NO}\left(\mathrm{g}\right)}$