1)Al→AlCl₃→Al(NO₃)₃→AI(OH)₃→Al₂O₃→Al₂(SO₄)₃
2Al + 6HCI=2AlCl₃+3H₂
AlCl₃ + 3HNO₃=Al(NO₃)₃+3HCI
Al(NO₃)₃ +3 NaOH=AI(OH)₃↓ + 3NaNO₂
2AI(OH)₃+ t =Al₂O₃ +3H₂O
Al₂O₃ + 3H₂SO₄=Al₂(SO₄)₃+3H₂O
2) Ca→Ca(OH)₂→Ca(NO₃)₂→CaSO₃→SO₂→H₂SO₃→Na₂SO₃
Ca + 2H₂O= Ca(OH)₂+H₂
Ca(OH)₂ + 2HNO₃= Ca(NO₃)₂+ 2H₂O
2Ca(NO₃)₂+t = 2CaO + 4NO₂↑ +O₂↑
CaO + SO₂= CaSO₃
CaSO₃+ H₂SO₄= CaSO₄ + SO₂↑+H₂O
SO₂ +H₂O=H₂SO₃
H₂SO₃ + 2NaOH=Na₂SO₃+2H₂O