Calculate what percent of the magnesium metal formed the nitride in the initial heating.
In this lab we heated a magnesium ribbon in a crucible to produce the MgO. The point was to discover it's Empirical Formula. Knowing that room air contains N2 as well as O2 we added H2O to get rid of the Mg3N2. However they want us to figure out the amount of Mg3N2 prior to the ad of water.
Mass of Mg after heating = 0.274 g which should contain MgO &Mg3N2.
Mass of Mg ribbon prior to Heating = 0.172 g
Mass after adding 2.0 mL of H2O & heating again = .283 g which should now only contain the MgO