3. urgeeeeennnntttt vaaaa rooogggg daaauuuu coroanaaa

Răspuns:
H2+Cl2= 2HCl
CuCO3 = CuO+CO2
Zn +2HCl=ZnCl2 +H2
2NaOH+CuSO4=Na2SO4+Cu(OH)2