2Na+Cl2--->2NaCl
CaO+CO2--->CaCO3
CuSO4+2NaOH--->Cu(OH)2↓+Na2SO4
3CaCl2+2Na3PO4--->Ca3(PO4)2↓+6NaCl
SO2+2NaOH--->Na2SO3+H2O
H2SO4+Zn--->ZnSO4+H2
2KOH+H2SO3--->K2SO3+2H2O
