4.
(1)
1) Ca + 2H₂O → Ca(OH)₂ + H₂↑
2) Ca(OH)₂ + CO₂ → CaCO₃↓ + H₂O
3) CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂
4) Ca(HCO₃)₂ + Ca(OH)₂ → 2CaCO₃↓ + 2H₂O
5) CaCO₃ (t°) → CaO + CO₂↑
(2)
1) 4Al + 3O₂ → 2Al₂O₃
2) Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O
3) AlCl₃ + 3NaOH → Al(OH)₃↓ + 3NaCl
4) Al(OH)₃ + H₂SO₄ → Al(HSO₄)₃ + 3H₂O
(3)
1) Сu + 4HNO₃ → Cu(NO₃)₂ + 2NO₂↑ + 2H₂O
2) Cu(NO₃)₂ + 2NaOH → Cu(OH)₂↓ + 2NaNO₃
3) Cu(OH)₂ (t°) → CuO + H₂O
4) CuO + H₂SO₄ → CuSO₄↓ + H₂O
5) CuSO₄ + H₂S → CuS↓ + H₂SO₄
(4)
1) 2Zn + O₂ → 2ZnO
2) ZnO + 2HNO₃ → Zn(NO₃)₂ + H₂O
3) Zn(NO₃)₂ + 2KOH → Zn(OH)₂↓ + 2KNO₃
4) Zn(OH)₂ + HNO₃ → ZnOHNO₃ + H₂O
(5)
1) 4К + О₂ → 2К₂О
2) K₂O + H₂SO₄ → K₂SO₄ + H₂O
3) K₂SO₄ + 2NaOH → 2KOH + Na₂SO₄
4) 2KOH + Zn → K₂ZnO₂ + H₂↑