A exothermic reaction it is any chemical reaction that gives off energyMeanwhile, we call chemical reaction or chemical modification the chemical process in which two or more substances (reactants), by the action of an energy variable, become other substances called products; substances can be elements or, failing that, compounds. For example, iron oxide is the chemical reaction resulting from the reaction of oxygen in the air with iron.
The exothermic reaction occurs especially in those oxidation reactions, which are the chemical reactions in which there is an electronic transfer between the reactants, giving way to a modification of the oxidation states of those mentioned in relation to the products. In other words, for an oxidation reaction to take place in the system in question, there must be an element that gives up electrons and another that accepts them.
It should be noted that when the oxidation reaction is intense it can give way to fire.
Known exothermic changes include: condensation, the transition from a gaseous state to a liquid state and the solidification, which is the transition from a liquid state to a solid state.
The most common example of an exothermic reaction is combustion, giving off an enormous amount of light and heat. In combustion we find an element that burns, which is fuel and another, an oxidizer, which is the one that produces combustion; most of the time it is oxygen in a gaseous way.
The reaction that opposes the exothermic is the endothermic reaction in which, on the contrary, it is a chemical reaction that absorbs energy.
