Name

Period

Date

Empirical Formula of MgO Lab

OBJECTIVE

• Burn magnesium to produce magnesium oxide, MgO, then determine its empirical formula.

INFO

• Mg molar mass = 24.312 g/mol
• O molar mass = 15.999 g/mol

MATERIALS

• bunsen burner
• ring stand, ring, clay triangle
• crucible
• tongs, leather gloves
• magnesium ribbon

DATA

1. mass of crucible & lid = g
2. mass of crucible & lid and magnesium = g
3. mass of crucible & lid and magnesium oxide = g

PROCEDURE

1. zero balance
2. mass out crucible
3. place Mg into crucible and mass out
4. heat crucible until all Mg has reacted with oxygen in air
5. use tongs to move crucible (hot!)
6. mass out crucible and magnesium compound

CALCULATIONS

1. mass of magnesium =
2. moles of magnesium =
3. mass of magnesium oxide =
4. mass of oxygen =
5. moles of oxygen =
6. mole ratio =
7. percent error =

CONCLUSION

• predicted empirical formula for magnesium oxide
• divide the moles of Mg into the moles of O, and use this as your experimental value (WYG)
• use the value of one, 1, as your expected value (WYSHG)
• calculate the percent error