A teacher uses this apparatus to test the products of the combustion of liquid hydrocarbons. burner. U-tube ice and water limewater to pump The teacher burns 30.0 g of heptane.. This is the equation for the complete combustion of heptane. CH₁6 +110, 7CO2 + 8H₂O Calculate the minimum mass of oxygen needed for the complete combustion of 30.0 g of heptane. [for CH16, M, 100 for O₂, M. = 32] (3) minimum mass of oxygen = 9 ​