✔ 最佳答案
Molar mass of NaCl = (23.0 + 35.5) g/mol = 58.5 g/mol
Molar mass of Na₂SO₄ = (23.0×2 + 32.1 + 16.0×4) g/mol = 142.1 g/mol
1 mole of NaCl contains 1 mole of Na⁺.
No. of moles of Na⁺ in NaCl = [(5.32 g) / (58.5 g/mol)]
1 mole of Na₂SO₄ contains 2 moles of Na⁺.
No. of moles of Na⁺ in Na₂SO₄ = [(1.20 g) / (142.1 g/mol)] × 2
Total number of moles of Na⁺ = [(5.32 g) / (58.5 g/mol)] + [(1.20 g) / (142.1 g/mol)] × 2 = 0.108 mol
Volume of the solution = 135 mL = 0.135 L
Molarity of Na⁺ = (0.108 mol) / (0.135 L) = 0.8 mol/L = 0.8 M