Gaseous ethane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 10.5 g of ethane is mixed with 76. g of oxygen. Calculate the minimum mass of ethane that could be left over by the chemical reaction. Be sure your answer has the correct number of significant digits. 2 C2H6 + 7 O2 = 4 CO2 + 6 H2O