Introduction to Combustion.

More than thousand years ago, ancient human beings discovered a mysterious thing called ‘fire’.

Discovery of fire revolutionized the way we lead our lives.

Man learned to use fire so as to ensure food and warmth.

Some even considered fire to be God.

And few others thought fire to be a fundamental substance along with earth, air and water.

But modern scientists said that ‘fire’ is not a substance.

It is rather a chemical process.

A process in which a substance is burnt with oxygen to give off heat and light.

This is exactly how we define ‘Combustion’.

Combustion is a chemical change where a substance combines with oxygen to give off heat or light.

Let us look at a few substances which undergo combustion.

One common combustion process that we observe everyday is wood burning.

When wood burns it produces new substances like carbon dioxide and water along with the evolution of heat and light.

Some other common examples of combustion process are burning of firecrackers, or forest fire.

Metals like magnesium too undergo combustion.

In this process, a new substance called magnesium oxide is formed along with the production of heat and light.

Similarly, sodium undergoes combustion to form sodium oxide along with the production of heat and light.

These are just a few examples of substances undergoing combustion. However, there are many such changes going around all the time.

Let us now go on to find out if every change that produces heat and light is a combustion reaction.

The sun provides heat and light.

But to provide heat and light it does not undergo a combustion reaction, instead it undergoes a special type of reaction called nuclear reaction.

Thus, we can say that all changes that produce heat and light are not combustion reactions.

Revision

Combustion is a chemical process in which a substance combines with oxygen to give off heat and light.

Burning of firecrackers, wood, forest fire are all examples of combustion reactions.

Burning of metals like magnesium, sodium are also combustion reactions.

The end!