100 ! 8 класс, с уравнениями реакций: з) ca -> ca(oh)2 -> ca(no3)2 -> caso3 -> so2 -> h2so3 -> na2so3 и) al -> alcl3 -> al(no3)3 -> al(oh)3 -> al2o3 -> al2(so4)3 к) ba(no3)2 -> hno3 -> mg(no3)2 -> mg(oh)2 -> mgo -> mgcl2

Решение:
З) Ca+2H₂O=Ca(OH)₂+H₂↑
Ca(OH)₂+2HNO₃=Ca(NO₃)₂+2H₂O
Ca(NO₃)₂+Na₂SO₃=2NaNO₃+CaSO₃↓
CaSO₃+2HCl=CaCl₂+SO₂↑+H₂O
SO₂+H₂O=H₂SO₃
H₂SO₃+2NaOH=Na₂SO₃+2H₂O

И) 2Al+6HCl=2AlCl₃+3H₂↑
AlCl₃+3AgNO₃=Al(NO₃)₃+3AgCl↓
Al(NO₃)₃+3NaOH=3NaNO₃+Al(OH)₃↓
2Al(OH)₃=Al₂O₃+3H₂O
Al₂O₃+3H₂SO₄=Al₂(SO₄)₃+3H₂O

К) Ba(NO₃)₂+H₂SO₄=2HNO₃+BaSO₄↓
2HNO₃+Mg=Mg(NO₃)₂+H₂↑
Mg(NO₃)₂+2NaOH=Mg(OH)₂↓+2NaNO₃
Mg(OH)₂=MgO+H₂O
MgO+2HCl=MgCl₂+H₂O