Question

S-->FeS-->H2S-->SO2-->Na2SO3-->NaSO4-->BaSO4

Answer 1

1)S+Fe=FeS

2)Fes+2HCl=H2S+FeCl2

3)H2S+3O2=2SO2+2H2O

4)SO2+Na2O=Na2SO3

5)2Na2SO3+O2=2Na2SO4

6)Na2SO4+BaCl2=2NaCl+BaSO4