Fire has been known to man as one of the most ancient “fundamental elements” in the world. But what is fire made of exactly?
Chemically, fire is made of carbon dioxide, water vapor, oxygen, and nitrogen.
It is produced through a special process called combustion. With a complex process and combination of four special elements, fire comes into existence.
If you’re interested in finding out about the whole process, stay with us till the end.
What Is Fire Made of?
Four elements make up the fire — an oxidizing agent, heat, fuel, and chemical reaction. These four elements are known as the fire tetrahedron. All of these elements must be present for a fire to occur.
Among these four components, oxidizing agent, heat, and fuel are known combinedly as the fire triangle.
Oxygen in the atmosphere is the oxidizing agent here usually, and the fuel is either a solid, liquid, or gas capable of combustion.
The chemical reaction is an exothermic reaction where heat is generated so there is more ignition of fuel.
The four elements of the tetrahedron work together to produce fire.
Heat causes the fuel to liberate vapors for ignition while atmospheric oxygen reacts with the fuel vapor to start the process of combustion.
Lastly, an exothermic reaction occurring as a result of combustion generates an additional amount of heat energy.
This heat is responsible for the liberation of more fuel vapor that sustains the fire.
In the case of forest fires, high atmospheric temperature and reduced humidity are responsible to a maximum extent.
Timber litter, shrubs, and grass can fuel a forest fire, and this kind of fire spreads at an uncontrolled rate.
Chemical Reaction in Fire
A chemical reaction called combustion is responsible for the production of fire. Flames are produced at the ignition point of combustion.
The chemical composition of these flames includes water vapor, oxygen, nitrogen, and carbon dioxide.
Combustion is a reaction when a fuel combines with oxygen and results in the liberation of energy.
Due to the rapid combination of oxygen and other substances, light and heat are produced from fire.
Fuel must be heated to its ignition point for combustion to take place.
The presence of a combustible substance, high temperature, and sufficient atmospheric oxygen leads to the formation of fire.
In complete combustion, there is no additional product produced from the burning fuel. Only carbon dioxide and water are produced in this type of combustion. Complete combustion takes place when there is enough oxygen concentration to react with the fuel gas.
Typically, blue flames are produced as a result of complete combustion.
You won’t find any smoke emitting from complete combustion process.
In case of incomplete combustion, there are other products produced other than carbon dioxide and water. Some of these products include carbon and carbon monoxide.
During an incomplete combustion, typically yellow or orange flames are produced.
Incomplete type of combustion always results in the emission of smoke.
State of Matter of Fire
Flames consist primarily of hot, fuming, and volatile gases.
Some of these gases are oxygen, vaporized fuel, carbon monoxide, and water vapor.
Fire sustained for a long time leads to the liberation of heat energy that further forms gaseous ions.
The state of matter achieved through this process is called plasma.
Flames in a very hot fire are responsible for producing the plasma state. The plasma state is called the fourth state of matter.
How Light and Heat Energy Is Produced in Fire?
Fire generates heat and light energy because of the exothermic chemical reaction. The mixture of fuel, oxygen, and heat leads to the formation of flames.
There is a huge amount of energy released during combustion reactions that sustain the production of flames.
As long as the elements are present, combustion continues and more flames are produced — resulting in fire. The flame ignites gases, and thus, fire perpetuates at a uniform rate.
Thus, the energy released by the combustion reaction is significantly more than the energy required to perpetuate the combustion.
There is more heat energy generated in the process, which is why fire is hot no matter what fuel is being used.
Meanwhile, light is produced from the burning flame when the excited electrons move within the shells and descend to lower orbitals.
This leads to the liberation of light energy.
The chemical composition of a candle flame includes a combination of many hot gases, including volatile paraffin wax and air.
The paraffin combines with the oxygen present in the air to form CO2 along with light and heat.
In order for a fire to occur through the combustion process, fuels must surpass the ignition temperature. So, this is one of the most important properties of a fuel that produces fire.
But what is this ignition temperature?
In the combustion reaction, there is a certain point at which flames are produced.
The combustion process of the fuel becomes self-sufficient beyond this certain point. This point is known as the ignition point or temperature.
When there is enough heat available to raise the substance to its ignition temperature, a fire occurs.
How Things Ignite
Now that you know how fire is made, let’s have a look at how things ignite and result in burning.
The combustion process only takes place through the reaction between gases. A fuel undergoes heating in this process and releases gases from the surface.
These gases are built with molecules that disintegrate upon reaching a high temperature.
The gas molecules combine with atmospheric oxygen and produce CO2 (carbon dioxide) and water molecules.
This is how things ignite, heated molecules form gases, and start the process of burning.
So, what is fire made of? A lot goes into the making of fire. With sufficient heat, fuel, and oxygen an exothermic reaction to stimulate the entire process, fire is conceived.
We hope our detailed discussion was helpful for you to figure out the entire development process of fire.