SO2, H2SO4, Ba(OH)2, CaO, H3PO4, NaOH, BaCl2
Ba(OH)2+SO2= 2BaSO3+ H2O
SO2+CaO=CaSO3
SO2+2NaOH=Na2SO3+H2O
H2SO4+Ba(OH)2=BaSO4+2H2O
H2SO4+CaO=CaSO4+H2O
H2SO4+NaOH=Na2SO4+H2O
H2SO4+BaCl2=BaSO4+2HCl
3Ba(OH)2+2H3PO4=Ba3(PO4)2+6H2O
3CaO+2H3PO4=Ca3(PO4)2+3H2O
CaO+BaCl2=CaCl2+BaO
H3PO4+3NaOH=Na3PO4+3H2O
2H3PO4+3BaCl2=Ba3(PO4)2+6HCl