Cu-CuSO4-Cu(OH)2-CuO-Cu
Cu+2H₂SO₄=CuSO₄+SO₂↑+2H₂O CuSO₄+2NaOH=Na₂SO₄+Cu(OH)₂↓ Cu(OH)₂=t=CuO↓+H₂O↑ CuO+H₂=Cu↓+H₂O