1)Na2CO3+2HCl=2NaCl+H2O+CO2
2Na+CO3+2H+2Cl=2Na+2Cl+H2O+CO2
CO3+2H=H2O+CO2
2)CuSO4+2NaOH=Na2SO4+Cu(OH)2
Cu+SO4+2Na+2OH=2Na+SO4+Cu(OH)2
Cu+2OH=Cu(OH)2
3)Cu(OH)2+2HCl=CuCl2+2H2O
Cu(OH)2+2H+2Cl=Cu+2Cl+2H2O
Cu(OH)2+2H=Cu+2H2O
4)NaOH+HCl=NaCl+H2O
Na+OH+H+Cl=Na+Cl+H2O
OH+H=H2O