Question

Explain why ozone is thermodynamically less stable than oxygen.

Answer 1

Hint: Ozone undergoes decomposition reaction. It breaks out to form oxygen which leads to increase in entropy.

Complete step by step answer:
- If a substance is unstable then it tends to decompose into other products which are more stable. They generally break out into their constituent species. Ozone is comparatively less stable than ozone. The proof of this statement is that energy is released when the ozone gets converted to oxygen. That means the decomposition of ozone is an exothermic reaction and energy or enthalpy change is negative.
- Ozone decomposes into the atomic oxygen and oxygen gas. The entropy of the system also increases because 1 substance gives rise to two substances. The entropy change is positive. The Gibbs free energy change for the decomposition ozone will be negative. This means the reaction is spontaneous in nature or happens on its own. The reaction will be spontaneous when the product formed is more stable than reactants. If the oxygen formed would be less stable then the reaction won’t go on its own we had to provide external energy.
Hence, ozone is less stable than oxygen.

Note:
The molecular formula is \[{{\text{O}}_3}\]. It is one of the Allotropes of oxygen allotropes that are made up of the same element but have different composition. Diatomic oxygen and ozone are both the allotropes of element oxygen. Ozone is a pungent smelling gas. Ozone is formed when UV or ultraviolet radiation falls over oxygen gas. Ozone is used in the preparation of pharmaceuticals, lubricants and to synthesis many useful organic compounds.