In experiment 5, the crucible, crucible cover, and magnesium are all measured separately to minimize percent error of the experiment. The crucible weighed 25.382g, while the cover weighed 21.479g and the magnesium’s weight was 0.419g. The total weight of the crucible, cover, and magnesium was calculated twice before burning the magnesium each was 47.28g and after burning the magnesium, which was 47.453g. To gain the mass of the magnesium oxide, the initial weight was subtracted from the final weight, which was .592g. To calculate the mass of oxygen in magnesium oxide, the mass of magnesium was subtracted from the mass of magnesium oxide which equaled 0.173g. To find the experimental mass ratio of oxygen in magnesium oxide, the mass oxygen in