For chemistry I am doing a lab and don't understand. So 1 gram of magnesium was used to create 1.65 grams of magnesium oxide, and 1.3826 grams of...

For chemistry I am doing a lab and don't understand. So 1 gram of magnesium was used to create 1.65 grams of magnesium oxide, and 1.3826 grams of magnesium nitride. Water was used in the lab to be mixed with the magnesium nitride to rid it of nitrogen, and then it was reheated to leave only magnesium oxide. When this reheating occurred would the mass of the final product be increased or decreased based on the numbers given of 1 gram of magnesium creating 1.65 grams of magnesium oxide, and 1.3826 grams of magnesium nitride.