1) S→SO₂→Na₂SO₃→SO₂;
S+O₂=SO₂;
SO₂+2NaOH=Na₂SO₃+H₂O;
Na₂SO₃+2HCl=SO₂+2NaCl+H₂;
2) Mg→MgO→MgSO₄→Mg(OH)₂;
2Mg+O₂=2MgO;
MgO+Na₂SO₄=MgSO₄+Na₂O;
MgSO₄+2KOH=Mg(OH)₂+K₂SO₄.
1) S→SO₂→Na₂SO₃→SO₂;
S+O₂=SO₂;
SO₂+2NaOH=Na₂SO₃+H₂O;
Na₂SO₃+2HCl=SO₂+2NaCl+H₂;
2) Mg→MgO→MgSO₄→Mg(OH)₂;
2Mg+O₂=2MgO;
MgO+Na₂SO₄=MgSO₄+Na₂O;
MgSO₄+2KOH=Mg(OH)₂+K₂SO₄.