Moles of oxygen atoms per gram depend on formula mass and oxygen count per molecule Steps: - Determine relative formula masses: Al₂O₃ = 102, CuSO₄ = 159.5, H₂SO₄ = 98, HNO₃ = 63. - Calculate moles of each compound in 1 g: 1/Mr (Al₂O₃: 0.0098 mol, CuSO₄: 0.0063 mol, H₂SO₄: 0.0102 mol, HNO₃: 0.0159 mol). - Multiply by oxygen atoms per formula: Al₂O₃ (×3) = 0.0294 mol O, CuSO₄ (×4) = 0.0251 mol O, H₂SO₄ (×4) = 0.0408 mol O, HNO₃ (×3) = 0.0476 mol O. - Compare: HNO₃ has the highest moles of oxygen atoms. Why D is correct: - HNO₃'s low formula mass (63) and 3 oxygen atoms per molecule maximize moles of O atoms per gram, as moles = (mass / Mr) × O count. Why the others are wrong: - A: Al₂O₃'s high Mr (102) yields fewer moles despite 3 O atoms. - B: CuSO₄'s highest Mr (159.5) results in the lowest moles even with 4 O atoms. - C: H₂SO₄'s Mr (98) is higher than HNO₃'s, so 4 O atoms give fewer total moles of …