S-SO2-SO3-H2SO4-MgSO4-Mg(OH)2-Mg(NO3)2
S+CO2=SO2+C SO2+O2=SO3 SO3+H2O=H2SO4 H2SO4+MgCl2=MgSO4+2HCl MgSO4+2NaOH=Mg(OH)2+Na2SO4 Mg(OH)2+2HNO3=Mg(NO3)2+2H2O