Ba-BaO-BaSO4-BaCI2==
Ba+O2=BaO BaO+H2So4=BaSo4+H20 BaSo4+HCl=BaCl2+H2So4
2Ba + O2=2BaO
BaO+H2SO4=BaSO4+ H2O
BaSO4+2HCl=BaCl2+H2SO4