1. The iron sulfide
To the lump iron sulfide is added hydrochloric acid (1:1).
2. The aluminum sulfide
Lump aluminum sulfide is added hydrochloric acid. The prepared sulphide has greater purity than prepared from iron sulfide.
3. The paraffin and sulfur
50 g melted paraffin (wax), add 20 g of sulfur and 10 g of alumina. This mixture will create beads. On the evolution of hydrogen sulphide ball just melt in the tube and after a while it starts to evolve hydrogen sulfide
Aluminum oxide acts as a catalyst.