Question

Why is decomposition of vegetable matter into compost considered an exothermic reaction?

Answer 1

Let’s first see what exothermic means. The term exothermic process describes a process or reaction that releases energy from the system to its surroundings, usually in the form of heat, but also in the form of light, electricity, or sound. Exothermic reactions usually release heat and entail the replacement of weak bonds with stronger ones. Most of the spectacular chemical reactions that are demonstrated in classrooms are exothermic and exergonic.

Complete answer:
Decomposition is a type of chemical reaction. Chemical decomposition is the process or effect of simplifying a single chemical entity into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. The details of a decomposition process are not always well defined but some of the process is understood that much energy is needed to break bonds.
The decomposition of vegetable matter into compost in an exothermic reaction because microbes need energy to break the bond of the vegetable . That's why it produces heat energy hence this decomposition reaction is an exothermic reaction. This decomposition process, which is carried out by microbes, requires energy to break down the bonds of vegetables. As a result, energy is released in the form of light.

Note:
All the decomposition reactions are usually endothermic because they are involved in the breaking of bonds. The breaking of bonds usually requires an input of energy and thus making it endothermic. Not all decomposition reactions are endothermic. A decomposition reaction can be both endothermic and exothermic.