What is incomplete combustion?

This is when there is not enough oxygen available for a fuel to burn fully and form carbon dioxide and water. As a result, the poisonous gas, carbon monoxide may be formed or even just carbon on its own (soot).

incomplete combustion is when the fuel does not burn in sufficient oxygen and therefore produces carbon monoxide, carbon in the form of soot and water

Incomplete combustion is what happens when there isn't enough oxygen or the supply of oxygen is poor. Whereas in normal (complete) combustion you would have the following equation:

hydrocarbon + oxygen -> water + carbon dioxide

in incomplete combustion you would have:

hydrocarbon + oxygen -> carbon monoxide + carbon + water

because there isn't enough oxygen to make both the water and carbon dioxide. This means that carbon monoxide gets made instead and, if there's any carbon left when all the oxygen is used it becomes soot.

Hope this helps!

Incomplete combustion is when the oxygen supply for the reaction is limited.

Water is still produced but instead of carbon dioxide, the odourless toxic gas carbon monoxide is produced.

when a fuel burn in limited supply of oxygen it will produce carbon monoxide and water

This is burning in a limited amount of Oxygen. It is a less efficient type of burning (meaning it gives off less energy). It releases toxic Carbon Monoxide and water as products.

This is where there is a limited oxygen supply, less than required. So carbon monoxide is produced alongside carbon dioxide and water. So there are three products in the equation compared to two in complete combustion.

Fuels are normally hydrocarbons - molecules that are made up of only atoms of hydrogen and carbon. When these fuels combust, these atoms react with the oxygen in the air to form oxides.

Hydrogen atoms will form water molecules

Carbon atoms will either form carbon monoxide or carbon dioxide

If there is plenty of oxygen then carbon will form carbon dioxide and we call this complete combustion. If there is not enough oxygen then carbon can only form carbon monoxide and we call this incomplete combustion.

Incomplete combustion is particularly dangerous as carbon monoxide is toxic and can cause death.

Combustion in limited supply of oxygen

Incomplete burning of fuel as a result of lack of oxygen

First we need to understand what is combustion?

Combustion is an exothermic redox reaction that occurs in the presence of an oxidant, usually atmospheric oxygen, that produces oxidized gaseous product, in a mixture called as smoke.

Now, we need to understand what is limiting reactant.

Limiting reactant is the reactant that is present in a limited amount and is consumed first. The amount of product formed is limited by this reactant, since the reaction cannot proceed further without it.

Now we'll be able to understand well what is incomplete combustion.

Since we know that combustion is the burning in the presence of oxygen.

Incomplete combustion is the reaction when there is not enough oxygen to allow the fuel to burn/react completely in order to produce carbon dioxide and water. So here Oxygen is the limiting reactant.

If carbon dioxide and water are not the product of incomplete combustion then what else?

Burning of fuel in limited amount of oxygen gives us Carbon monoxide and water.

When substances have reacted with insufficient oxygen and will produce carbon monoxide (CO) and water (H2O).

Incomplete combustion is when there is insufficient oxygen for burning and carbon monoxide and carbon (soot) is produced as well as carbon dioxide. Complete combustion , if possible, would produce only carbon dioxide.

This is when complete combustion isn't able to occur due to the lack of sufficient oxygen

This is when there is little or no oxygen available for combustion so instead of carbon dioxide being produced carbon monoxide is, this is poisonous.