Final answer:
The empirical formula of aluminum oxide, obtained by dividing the number of moles of aluminum and oxygen by the smallest number of moles present and converting to the simplest whole number ratio, is Al2O3.
Step-by-step explanation:
To find the empirical formula of aluminum oxide, we first convert the masses of aluminum and oxygen to moles by using their respective molar masses. The molar mass of aluminum (Al) is approximately 27 g/mol, and the molar mass of oxygen (O) is approximately 16 g/mol. Therefore, the number of moles of aluminum is 2.7 g / 27 g/mol = 0.1 mol, and the number of moles of oxygen is 2.4 g / 16 g/mol = 0.15 mol.
To find the empirical formula, we need to express the ratio of the moles of aluminum to oxygen in its simplest whole number ratio. In this case, dividing both by the smaller number of moles (0.1 mol), we get Al:O = 1:1.5. To convert this into a whole number ratio, we multiply both sides by 2 to get Al2:O3. Thus, the empirical formula for aluminum oxide is Al2O3.