a 9.6 gram piece of clean magnesium burned completely in 6.4 grams of pure oxygen and the product was allowed to cool at room temperature and pressure. Determine the reaction mole ratio and hence the formula for the oxide

1 answer

To determine the reaction mole ratio and the formula for the oxide, we need to first find the moles of magnesium and moles of oxygen involved in the reaction.

1. Calculate the moles of magnesium:
Molar mass of Mg = 24.31 g/mol
moles of Mg = mass of Mg / molar mass of Mg = 9.6 g / 24.31 g/mol ≈ 0.394 mol

2. Calculate the moles of oxygen:
Molar mass of O2 = 32.00 g/mol
moles of O2 = mass of O2 / molar mass of O2 = 6.4 g / 32.00 g/mol = 0.20 mol

The reaction mole ratio is the ratio of the moles of the reactants magnesium and oxygen. From the balanced chemical equation, we know that the ratio is 2 moles of Mg to 1 mole of O2.

Therefore, the mole ratio of magnesium to oxygen is 2:1.

Now, we can determine the empirical formula of the oxide. The empirical formula represents the simplest whole number ratio of the elements in a compound.

Since the ratio of Mg to O2 is 2:1, the empirical formula for the oxide is MgO.