Question

How do you explain the role of oxygen in the combustion process?

Answer 1

Hint: The chemical process where the substance burns to give off heat or sometimes light is called combustion.

Complete step by step answer:
 The process of combustion takes place on in the presence following three things:
-Fuel
-Oxidiser
-Source of heat
Oxygen plays the role of oxidizer. It is a very good oxidiser. The process of combustion involves the oxidation of fuel by the oxidiser to liberate heat. Hence is it the oxygen that oxidises the fuel to give off heat.
-Depending upon the by-products and energy requirements the combustion process is classified into five types, that are listed below:
1. Complete combustion: Complete burn of oxygen; requires fuel and oxygen
Incomplete combustion: Inadequate amount of oxygen for the fuel to undergo oxidation
2. Rapid combustion: External energy in the form is required. Complete use of fuel with large amounts of heat being released.
3. Spontaneous combustion: No need for external energy.
4. Explosive combustion: Causes heat, light and sound to be produced.
For instance, hydrocarbons such as methane undergo complete combustion to liberate carbon dioxide, water and heat. Methane gets completely burned in the presence of oxygen. This process of combustion can be represented as:
$\text{C}{\text{H}}_{\text{4}}\text{ + }{\text{O}}_{\text{2}}\to \text{C}{\text{O}}_{\text{2}}\text{ + 2}{\text{H}}_{\text{2}}\text{O + Heat}$
Combustion of fossil fuels such as coal may lead to the generation of renewable fuels that is used to power rockets, in cooking and also for industrial uses.

Note:
Combustion happens in the presence of oxygen. In the absence of oxygen, the process is known as pyrolysis. Pyrolysis is the decomposition of chemical substances in an inert atmosphere and requires high temperature.