Final answer:
The empirical formula of a compound containing 60.3% magnesium and 39.7% oxygen is determined by converting the percentage composition to moles and simplifying the mole ratio. The resulting empirical formula is MgO.
Step-by-step explanation:
To determine the empirical formula of a compound containing 60.3% magnesium and 39.7% oxygen, we start by assuming we have 100 grams of the compound. This means we have 60.3 grams of magnesium and 39.7 grams of oxygen. Next, we convert these masses to moles by dividing by their atomic masses (Mg = 24.31 g/mol, O = 16.00 g/mol):
- 60.3 g Mg ÷ 24.31 g/mol = 2.480 moles of Mg
- 39.7 g O ÷ 16.00 g/mol = 2.481 moles of O
The ratio of Mg to O is therefore roughly 2.480 : 2.481, which simplifies to approximately 1 : 1 when divided by the smallest number of moles. Thus, the empirical formula is MgO, which corresponds to option (A).