Explanation: Balance the following equation: C3H8 + O2 ----> CO2 + H2O. (There will be no need for state symbols.) First of all, to balance these equations, list the number of each atom, for both sides of the equation. In this example, it would be: The first step would be to balance out the carbons on the products side by multiplying CO2 by 3. The balanced chemical equation for C3H8 +O2 = CO2 + H2O is C3H8 +5O2 = 3CO2 +4H2O. This is the chemical reaction in which C3H8 or propane burns in air or oxygen to produce carbon dioxide and water.