The oxidation of organic compounds by molecular oxygen to produce carbon dioxide (CO2) and water is a chemical reaction that releases free energy. This reaction is an exothermic process, meaning that it releases energy in the form of heat. The release of energy occurs because the products of the reaction, CO2 and water, are more stable than the reactants, the organic compounds and oxygen.

The release of free energy during the oxidation of organic compounds can be explained using the concept of Gibbs free energy, which is a measure of the potential of a chemical reaction to do work. According to the second law of thermodynamics, the total entropy, or disorder, of a closed system must increase over time. This means that chemical reactions that produce more stable products will release energy as the system becomes more disordered.

In the case of the oxidation of organic compounds, the products, CO2 and water, are more stable than the reactants, which means that the reaction will release energy as the system becomes more disordered. The energy released during the reaction can be used to do work, such as powering the body’s metabolic processes or driving chemical reactions in other systems.

In summary, the oxidation of organic compounds by molecular oxygen to produce CO2 and water releases free energy because the products of the reaction are more stable than the reactants. This release of energy occurs as the system becomes more disordered and can be used to do work.