Empirical Formula of Magnesium Oxide

Empirical Formula of Magnesium Oxide

The purpose of this experiment is to determine the empirical formula of magnesium oxide.

Procedure:

1. Obtain a clean, dry crucible and lid.

2. Obtain a strip of magnesium ribbon.

3. Coil the magnesium ribbon, so that it fits into the crucible

4. Weigh crucible and lid on a balance, and record the mass

5. Place magnesium ribbon into crucible, replace the lid and weigh once more

6. Heat the crucible and its content with the lid off until the magnesium begins to smoke.

7. Replace the lid and heat the crucible strongly.

8. When all magnesium smoke has ceased then we removed the lid.

9. Replace crucible lid and allow to cool then add drops of water.

10. reheat then remove and let cool then weigh again.

Once the magnesium was in the crucible and was being heated by the Bunsen burner, we noticed nothing was happening. We then realized the crucible was set to high from the heat, so we reset the height. Then we saw that the magnesium started to glow for a brief time. It then caught a little fire and started to smoke. That is when we placed the lid on top. We then watched the smoke for quite a while. The smoke from the magnesium went on for a lot longer then we expected. We suspected that the magnesium strip might have been thicker or longer then everybody else. After the smoke ceased, we let it cool down. That is when we added a few drops of water to the crucible. We then reheated the crucible, magnesium, and water. Finally, we removed, let it cool down and re-weighed. Lastly, we started to calculated and determine the empirical formula for magnesium oxide.

Results:

Mass of crucible and lid 23.945 g

Mass of crucible, lid and magnesium 24.091 g

Mass of magnesium 0.146 g

Mass of crucible, lid and magnesium oxide 24.170 g

Mass of magnesium oxide 0.4 g

Mass of combined oxygen .079 g