Mass of Mg (g): 0.2000 Mass of oxide (g): 0.3317 1. Determine the empirical formula of the oxide of magnesium. (Think carefully about the precision of each mass that you measured before you do this calculation. How many significant figures are justified for each mass?) 2. Write the correctly balanced chemical equation for the reaction of magnesium with molecular oxygen. 3. Write the correctly balanced chemical equation for the reaction of magnesium with molecular nitrogen. 4. Write the correctly balanced chemical equation for the reaction of magnesium nitride with water. 5. Write the correctly balanced chemical equation for the reaction of heating magnesium hydroxide

1. Empirical formula is MgO

2. 2Mg + O₂ --> 2MgO

3. 3Mg + N₂ ---> Mg₃N₂

4. Mg₃N₂ + 6H₂O > 3Mg(OH)₂ + 2NH₃

5. Mg(OH)₂ ---> MgO + H₂O

Explanation:

1. Empirical formula:

mass of magnesium oxide = 0.3327 g; mass of magnesium = 0.2000 g

mass of oxygen = 0.3317 g - 0.2000 g = 0.1317 g

molar mass of magnesium = 24, molar mass of oxygen = 16

molar ratio of magnesium to oxygen is then calculated;

magnesium = 0.2000/24 = 0.0083 : oxygen = 0.1317/16 = 0.0082

magnesium = 0.0083/0.0082 = 1 : oxygen = 0.0082/0.0082 = 1

molar ratio of magnesium to oxygen = 1 : 1

Therefore, empirical formula is MgO

2. The reaction of magnesium with molecular oxygen produces magnesium oxide as shown by the equation below:

2Mg + O₂ --> 2MgO

3. The reaction of magnesium with molecular nitrogen produces magnesium nitride as shown by the equation below:

3Mg + N₂ ---> Mg₃N₂

4. The reaction of magnesium nitride with water produces magnesium hydroxide and ammonia gas as shown by the equation below:

Mg₃N₂ + 6H₂O > 3Mg(OH)₂ + 2NH₃

5. The products of the reaction of heating magnesium hydroxide are magnesium oxide and water as shown by the equation below:

Mg(OH)₂ ---> MgO + H₂O