Why does the water not burn? And what are the reasons?
Some may ask why water does not burn, even though it consists of flammable hydrogen and oxygen, which helps in ignition, as its chemical composition is hydrogen oxide? While hydrogen sulfide gas ignites or burns easily, not only water does not burn, but there are other compounds that do not burn, for example, carbon dioxide gas that is used to extinguish fires also does not burn.
Before we explain this, we must know the meaning of combustion and its factors .
Combustion can be defined as a chemical reaction that usually occurs between oxygen and another flammable or combustible substance in the presence of auxiliary factors, for example, the combustion of gasoline or the combustion of wood accompanied by flame and heat. According to this definition, it becomes clear to us that the basic combustion elements are oxygen, a flammable substance (fuel) and sufficient heat to start the ignition process. In other words, it is an oxidation reaction where oxygen oxidizes the oxidizable substance.
And the chemical reaction, whether it is combustion or other reactions that occur between materials, is the process of redistributing the outer electrons of the interacting atoms by sharing or gaining and losing in a way that leads to the formation of new materials that are the products that differ in their nature and physical and chemical properties from the reactants.
This distribution process is done by breaking the bonds or bonds between the interacting atoms to produce new bonds between the atoms of the resulting materials. How do these operations take place? According to Kinetic science, a reaction occurs when the reactants have more energy than the minimum energy required for the reaction to occur, which is called the activation energy.
To clarify the picture, we take the following example: When a diatomic iodine molecule approaches a diatomic hydrogen molecule, this convergence forms a temporary space arrangement so that these four atoms are linked to each other and quickly disintegrate to give two molecules of hydrogen iodide.
According to the activation energy, the nature of the interaction between the materials varies, some of them are fast, some are slow, and others do not happen at all, as it is in the attempt to burn water. When the oxygen atoms and water molecules approach each other in the presence of a flame or high heat, no interaction occurs for the following reasons.
Reasons why water does not burn
First: The way the atoms collide with each other did not enable them to form a new product
Second: The spatial position of the colliding atoms is not suitable for the reaction to occur and the formation of the product. Therefore, the close atoms were not able to arrange or form a temporary space complex (activated complex) from these close atoms. By raising the temperature, it cannot provide the activation energy for the reaction, which enables water to ignite.