A chemical reaction that produces heat is:

The term that describes a chemical reaction that produces heat is exothermic. In an exothermic reaction, energy is released into the surrounding environment when the reactants transform into products. This release of energy often manifests as heat, which can be sensed as an increase in temperature of the surroundings.

Exothermic reactions are prevalent in many chemical processes, such as combustion, where fuels react with oxygen and produce heat, light, and various products. Understanding this concept is crucial for fire fighters, as many fire incidents involve exothermic reactions, and recognizing their behavior can help in controlling and extinguishing fires effectively.

In contrast, an endothermic reaction absorbs heat, resulting in a drop in the temperature of the surroundings, while isothermic processes maintain a constant temperature and thermodynamic refers more broadly to the study of energy transformations rather than a specific type of reaction.