Magnesium can be used as a "getter" in evacuated enclosures to react with the last traces of oxygen. (The magnesium is usually heated by passing an electric current through a wire or ribbon of the metal.) If an enclosure of 0.452 L has a partial pressure of O2 of 3.5 x 10-6 torr at 27oC, what mass of magnesium will react according to the following equation?
2Mg (s) + O2 (g) → 2 MgO (s)