Okay friend, I will explain the answer clearly.

Combustion:- When the Carbon compounds are burnt, they release a large amount of heat and light on burning. This is called Combustion reaction.


Saturated Hydrocarbons and Unsaturated Hydrocarbons are the two types which burns on the process of combustion reaction.

*If the Saturated Hydrocarbons are burnt, it burns with the blue flame to release CO2 or CO and H2O along with the releasing of Heat.

[Note:- Blue colour flame indicates that the Hydrocarbons is burnt with the sufficient supply of Oxygen].


*If the Unsaturated Hydrocarbons are burnt, it burns with the yellow flame and release CO2, CO (incomplete combustion).

[Note:- Yellow colour flame indicates that the Hydrocarbons is burnt with the limited supply of Oxygen. It means, the Hydrocarbons is burnt without the sufficient supply of Oxygen].

If both Saturated and Unsaturated Hydrocarbons are burnt without the sufficient supply of Oxygen, this leads to give a sooty flame.

Sooty flame can occurs in Red colour flame and also Black colour flame friend..

You can also see the sooty flame in your daily life. In your home, if you have a stove with so many dust particles sitted on the stove, when you light the stove starting, you can observe the Red colour flame. And to observe the Black colour flame, Put some waste substances like Coconut chips in a small hole in order to burnt it, you can observe the Black colour flame due to the insufficient supply of Oxygen.

Here is the examples for the Combustion reaction friend.. is as below.

(i) C + O2 → CO2↑.
Carbon (C) reacts with Oxygen (O) to release Carbon dioxide gas (CO2).

(ii) CH4 + 2O2 → CO2 + 2H2O + Heat + light.
Methane (CH4) reacts with Oxygen (O2) to release Carbon dioxide (CO2), Water (H2O) along with the releasing of Heat and scatters light as you can observe the Chemical equation.

(iii) CH3-CH2OH + 3O2 → 2CO2 + 3H2O + Heat + light.
Ethanol (C2H5OH) reacts with Oxygen (O2) to release Carbon dioxide (CO2), Water (H2O) with the release of Heat and scatters light.

A combustion reaction is when a substance reacts with oxygen and releases a huge amount of energy in the form of light and heat. Acombustion reaction always has oxygen as one reactant. The second reactant is always a hydrocarbon, which is a compound made up of carbon and hydrogen.!!