- Fe(OH)3,BaCl2,CuO,HNO3.Fe ( OH )_{3}, Ba Cl _{2}, CuO , HNO _{3} .
- H2SO4,SO2,CO2,FeCl2H _{2} SO _{4}, SO _{2}, CO _{2}, FeCl _{2}
- HNO3,HCl,CuSO4,KNO3HNO _{3}, HCl , CuSO _{4}, KNO _{3}
- Al,MgO,H3PO4,BaCl2Al , MgO , H _{3} PO _{4}, Ba Cl _{2}