Question

Boiling is an exothermic change.

• A. True
• B. False

Answer 1

The correct option is B False

A. Boiling water

• Boiling of water is a physical change as boiling of water at $100°\mathrm{C}$ will change the liquid state of water from liquid to vapours.
• Heat is absorbed in this reaction which changes the state of water from liquids to vapour.
• It is not a permanent change as vapours can be converted back to liquid on cooling.

Endothermic change

• Those reactions in which energy is absorbed in the form of heat.
• For example, Boiling of water, sublimation etc.

Exothermic change

• Those reactions in which energy is released from heat and light.
• For example, Combustion reaction

$\underset{\mathrm{Methane}}{{\mathrm{CH}}_4\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{2{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)}$

Hence, boiling is an endothermic change.