Final answer:
The mass percent composition of oxygen in Al₂(SO₄)₃ is 56.11%.
Step-by-step explanation:
The mass percent composition of oxygen in Al₂(SO₄)₃ can be calculated by finding the mass of oxygen in the compound and dividing it by the total mass of the compound, then multiplying by 100.
The formula mass of Al₂(SO₄)₃ is 342.14 amu. From the formula, we can see that there are 12 oxygen atoms in the compound. To find the mass of oxygen, we multiply the molar mass of oxygen (16.00 g/mol) by the number of oxygen atoms, giving us 192.00 g/mol.
The mass percent composition of oxygen is therefore (192.00 g/mol / 342.14 g/mol) * 100 = 56.11%.