Place the crucible with lid and magnesium on the pipe clay triangle.
Heat vigorously with a blue flame with the lid secure.
On occasion, lift the lid slightly to observe the reaction process. You may blow softly into the reaction vessel to improve the reaction. Ensure the lid is closed when the reaction proceeds.
Once the reaction has stopped let the crucible cool.
Reweigh the crucible, lid and magnesium ribbon once cool.
Mass of lid + crucible
Mass of lid + crucible + magnesium
Mass of magnesium
Mass of lid + crucible + magnesium oxide
Mass of magnesium oxide
Compare the mass of the initial of magnesium and the final magnesium oxide? What do you notice in terms of the change in mass?
Is this what would be expected? You may wish to check with other groups to determine if there is a trend in changed mass.
Why did you think this mass change would occur?
Compare the actual yield with your calculated theoretical yield. Are they close? By what percentage of the expected result are you off?