Conc H2SO4 is not used in the preparation of H2S. Explain

Conc H2SO4 is not used in the preparation of H2S. Explain

Answer: Concentrated H2SO4 is not used in H2S preparation. Because concentrated H2SO4 is an oxidising acid; The H2S produced by the acid reaction with ferrous sulphide oxidizes concentrated H2SO4 to sulphur, which itself reduces to produce sulfur dioxide (SO2).

H2S + H2SO4 = S ↓ + SO2 ↑ + 2H2O