Be sure to answer all parts. Three of the reactions that occur when the paraffin of a candle (typical formula C21H44) burns are as follows: (1) Complete combustion forms CO2 and water vapor. (2) Incomplete combustion forms CO and water vapor. (3) Some wax is oxidized to elemental C (soot) and water vapor.

Combustion reaction is defined as the chemical reaction in which a hydrocarbon reacts with excess supply of oxygen gas to produce carbon dioxide gas and water molecule.

[tex]\text{Hydrocarbon}+O_2\rightarrow CO_2+H_2O[/tex]

When paraffin wax undergoes complete combustion, the chemical equation follows:

[tex]C_{21}H_{44}+32O_2\rightarrow 21CO_2+22H_2O[/tex]

For 2:

If supply of oxygen gas is limited, it is known as incomplete combustion and carbon monoxide gas is produced instead of carbon dioxide as a product. The chemical equation for this reaction follows:

[tex]\text{Hydrocarbon}+O_2\text{(limited)}\rightarrow CO+H_2O[/tex]

When paraffin wax undergoes incomplete combustion, the chemical equation follows:

[tex]2C_{21}H_{44}+43O_2\rightarrow 42CO+44H_2O[/tex]

For 3:

When paraffin wax undergoes oxidation to form elemental carbon and water vapor, the chemical equation follows:

[tex]C_{21}H_{44}+11O_2\rightarrow 21C+22H_2O[/tex]

Hence, the chemical equations are written above.