Решение:З) Ca+2H₂O=Ca(OH)₂+H₂↑Ca(OH)₂+2HNO₃=Ca(NO₃)₂+2H₂OCa(NO₃)₂+Na₂SO₃=2NaNO₃+CaSO₃↓CaSO₃+2HCl=CaCl₂+SO₂↑+H₂OSO₂+H₂O=H₂SO₃H₂SO₃+2NaOH=Na₂SO₃+2H₂OИ) 2Al+6HCl=2AlCl₃+3H₂↑AlCl₃+3AgNO₃=Al(NO₃)₃+3AgCl↓Al(NO₃)₃+3NaOH=3NaNO₃+Al(OH)₃↓2Al(OH)₃=Al₂O₃+3H₂OAl₂O₃+3H₂SO₄=Al₂(SO₄)₃+3H₂OК) Ba(NO₃)₂+H₂SO₄=2HNO₃+BaSO₄↓2HNO₃+Mg=Mg(NO₃)₂+H₂↑Mg(NO₃)₂+2NaOH=Mg(OH)₂↓+2NaNO₃Mg(OH)₂=MgO+H₂OMgO+2HCl=MgCl₂+H₂O