Chemical processes play a significant role in our daily lives and shape the environment in both visible and invisible ways. Chemistry is essential in explaining why and how these changes take place, from the fuel combustion that drives our cars to the photosynthesis process that keeps plants alive. But have you ever considered the reasons for chemical reactions? We will investigate the ‘why’ behind chemical reactions in this post as we dig into the fascinating realm of chemical reactions.

Principles of Chemical Reactions

A chemical reaction is fundamentally the reorganisation of atoms and molecules into new substances. These reactions can produce new compounds, the release of heat or light, changes in the physical state of matter, as well as the release or absorption of energy. But what causes and why do these changes take place?

  1. Entropy is the driving force

The idea of entropy is one of the fundamental ideas that underlies chemical processes. Entropy may be viewed as a way to quantify chaos or unpredictability in a system. Nature favours processes that generate chaos since it has a tendency towards increased entropy. Because they produce a more disordered state that is thermodynamically advantageous, chemical reactions frequently take place.

For instance, when wood burns, it reacts chemically with oxygen to create carbon dioxide and water vapour, which then releases heat and light. In this instance, the entropy increases and the reaction is spontaneous because the reactants (wood and oxygen) have less entropy than the products (carbon dioxide and water vapour).

  1. Energy’s Function: Activation Energy

Many reactions are driven by entropy, but energy concerns are also significant. The activation energy is the initial force required to initiate a reaction. Reactants must overcome this energy barrier in order to become products. When the activation energy is exceeded, the reaction enters a self-sustaining state and continues to release or absorb energy.

Think about how an engine burns petrol. A spark plug first supplies the required activation energy to light the fuel-air combination. Once the reaction is started, it continues and produces a significant quantity of energy in the form of heat, which drives the engine.

  1. Bond Energy: The Strength of Molecular Bonds

Chemical bonds between atoms and molecules can be formed and broken during chemical processes. The energy known as bond energy is distinct to each form of relationship. We must contrast the energy needed to break the bonds in the reactants with the energy released when new bonds form in the products in order to comprehend why a reaction takes place.

For instance, plants use sunlight to break the bonds between molecules of water and carbon dioxide during the process of photosynthesis. This releases oxygen and allows plants to store energy in the form of glucose. The reaction is energy-favorable because the energy required to break the bonds in water and carbon dioxide is larger than the energy acquired from the formation of glucose bonds.


The complicated dance of atoms and molecules, driven by the fundamental laws of thermodynamics and energy transmission, is the “why” of chemical processes. Systems are pushed towards increasing disorder by entropy, whereas reactions are started by activation energy and determined by bond energy. The ability to anticipate and control chemical processes is made possible by an understanding of fundamental principles, which has produced many inventions and advances in technology. The ‘why’ underlying chemical reactions will definitely reveal new and intriguing possibilities as we continue to delve into the field of chemistry, influencing how we view the natural world.