What is the primary outcome of a chemical reaction during combustion?

The primary outcome of a chemical reaction during combustion is the generation of heat and light. During combustion, a fuel reacts with an oxidizing agent, typically oxygen in the air, leading to a rapid release of energy. This exothermic reaction produces heat, which can cause temperatures to rise significantly, and light, which is often visible as flames.

While other products such as water and carbon monoxide may be generated during combustion, they are secondary results of this reaction. Water vapor, a product of the molecular combustion of hydrogen-bearing fuels, and carbon monoxide, which can be produced from incomplete combustion, are not the primary focus. Additionally, emissions like smoke, which often include soot and unburned particles, can occur as byproducts of combustion when fuel is not completely burned, but they do not define the fundamental nature of what happens during the reaction itself.

In essence, the hallmark of combustion is the transformation of chemical energy into thermal energy (heat) and electromagnetic energy (light), making the generation of heat and light the central outcome of this process.