Procedure:

1. Obtain crucible and lid and make sure it is not defected

2. Measure mass of crucible and lid

3. Place the crucible and lid on the clay triangle over the Bunsen burner and heat it until it’s red hot (about 15 minutes) and allow the crucible and lid to cool to room temperature

4. Measure the mass of the “fired” crucible

5. Repeat heating/cooling until two measurements are within 10 mg of each other

6. Obtain between 0.17 g and 0.23 g of magnesium power/chips and add it to the crucible

7. Measure the mass of the crucible, lid, and magnesium and return it to the clay triangle over the Bunsen burner

8. Heat the sample until it has a pale glow (about 10 minutes) and stop heating 

9. Let the crucible cool and mix its contents with a paper clip by breaking the crust over the contents

10. Repeat until no metal is visible

11. When the sample has cooled completely, add three drops of deionized water to the crucible

12. Heat the crucible slowly and leave the lid open for water vapor to escape until the sample has a pale glow, then stop the heating and let the crucible cool to room temperature with the lid on

13. Measure the mass of the crucible, lid, and metal oxide

14. Repeat until two consecutive readings are within 10 mg

15. Dispose of the metal oxide, wash the crucible, and clean up