CaO+2HCl=CaCl2+H2O CaO+SO2=CaSO3 2HCl+Ca(OH)2=CaCl2+2H2O HCl+NaOH=NaCl+H2O SO2+Ca(OH)2=CaSO3+H2O SO2+NaOH(разб)=NaHSO3 SO2+2NaOH(конц)=Na2SO3+H2O