Question

If heat is evolved during a reaction, it is _______

Answer 1

Exothermic reaction: It is defined as the reactions in which energy is released in the form of heat or light.

• These types of reactions are spontaneous in nature.
• Spontaneous reaction: The reactions which occur on their own.
• For example, The reaction between magnesium (Mg) and oxygen (O₂).

$\underset{\mathrm{Magnesium}}{2\mathrm{Mg}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Magnesium}\mathrm{Oxide}}{2\mathrm{MgO}\left(\mathrm{s}\right)}$

• The reaction is exothermic and will produce light.

Thus, If heat is evolved during a reaction, it is an exothermic reaction.