Cu->CuO->CuSO_4->^3Cu(OH)_2->CuO
1. 2Cu + O₂ =(t°)= 2CuO 2. CuO + H₂SO₄ = CuSO₄ + H₂O 3. CuSO₄ + 2NaOH = Cu(OH)₂ + Na₂SO₄ 4. Cu(OH)₂ =(t°)= CuO + H₂O