Question

what happens when iron and sulphur mixture and iron sulphide are treated with hydrochloric acid?

Answer 1

Iron react with Sulphur to form Iron sulphide

Part-1
Iron Sulphide react with HCl to release a rotten smell gas i.e H₂S

​Reaction Involved-

FeS + 2HCl → FeCl₂ + H₂S

Part-II
Similarly,
Iron Sulphide react with H₂SO₄ to release a rotten smell gas i.e H₂S​
FeS + H₂SO₄ → FeSO4 + H₂S