Magnesium burns in oxygen gas to produce magnesium oxide. What mass of magnesium will react with a 0.25 L container of oxygen gas at 80oC and 770 mmHg? I need to use stoichiometry to set up the pronlem and PV=nRT to solve. I have three possible solutions, but I don't know which one is the correct one. The solutions I have are .945 g, .418 g, and .124 g.