1. 2Cu + O₂ → 2CuO
2. CuO + 2HCl → CuCl₂ + H₂O
3. Ca(OH)₂ + CuCl₂ → Cu(OH)2↓ + CaCl₂
4. Cu(OH)₂ → CuO + H₂O
5. CuO + H₂↑ → Cu + H₂O
6. 2H₂SO₄ + Cu → CuSO₄ + SO₂↑ + 2H₂O
7. CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄
8. 2HNO₃ + Cu(OH)₂ → Cu(NO₃)₂ + 2H₂O
9. 2Cu(NO₃)₂ → 2CuO + 4NO₂ + O₂↑
1. 2Cu + O₂ → 2CuO
2. CuO + 2HCl → CuCl₂ + H₂O
3. Ca(OH)₂ + CuCl₂ → Cu(OH)2↓ + CaCl₂
4. Cu(OH)₂ → CuO + H₂O
5. CuO + H₂↑ → Cu + H₂O
6. 2H₂SO₄ + Cu → CuSO₄ + SO₂↑ + 2H₂O
7. CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄
8. 2HNO₃ + Cu(OH)₂ → Cu(NO₃)₂ + 2H₂O
9. 2Cu(NO₃)₂ → 2CuO + 4NO₂ + O₂↑