Methane (CH4) is the main component of natural gas. It is burned for fuel in a combustion reaction. The unbalanced combustion reaction for methane is shown below. CH4 + O2 CO2 + H2O + heat When the reaction is balanced, how many carbon dioxide molecules are produced for every methane molecule burned?

In order to balance reactions, we need to remember that both sides of the reaction should have the same number of atoms. This is to agree with the law of conservation of mass where it states that the sum of the mass inflow of a process should be equal to the sum of the mass out in the process since mass cannot be created or destroyed. We write the equation as

CH4 + O2 = CO2 + H2O

Reactant side Product side

C = 1 1

H = 4 2

O = 2 3

We need to balance the atoms. It should be as follows:

CH4 + 2O2 = CO2 + 2H2O