Question

1)S->H2S->FeS->FeSO4

2)H2SO4->BaSO4->BaCl2

Answer 1

1)
S+H2=H2S
H2S+Fe=FeS+H2
FeS+MgSO4=FeSO4+MgS
2)
H2SO4+Ba=BaSO4+H2
BaSO4+MgCl2=BaCl2+MgSO4