Na-NaOH-Fe(OH)2-Fe(OH)3-Fe2O3-Fe2(SO4)3-BaSO4
Na→NaOH→Fe(OH)₂→Fe(OH)₃→Fe₂O₃→Fe₂(SO₄)₃→BaSO₄ 2Na +2H₂O =2NaOH +H₂↑ 2NaOH + FeCI₂= Fe(OH)₂↓ +2NaCI 4Fe(OH)₂+O₂+2H₂O= 4Fe(OH)₃↓ 2Fe(OH)₃ + t= Fe₂O₃ + 3H₂O Fe₂O₃ + 3H₂SO₄= Fe₂(SO₄)₃ + 3H₂O Fe₂(SO₄)₃ + 3BaCI₂ = 3BaSO₄↓ + 2FeCI₃