25 cm³ of ethene is mixed with 60 cm³ of oxygen. The mixture is ignited forming CO2 and the H2O and H2O according to the equation C2H4 plus 3O2 is equal to 2CO2 plus 2H2O. The mixture is then allowed to cool to the original temperature and pressure. Calculate the volume left at the end of the reaction. Calculate the volume left at the end of the reaction.