Hydrogen diselenide
Hydrogen diselenide is an inorganic selenium compound with a chemical formula or. At room temperature, hydrogen diselenide dissociates easily to hydrogen selenide and elemental selenium, and is therefore not stable. When an aluminum-reduced hydrochloric acid solution of selenium dioxide is reacted with lead acetate, the resulting black precipitate contains lead diselenide ，this proves that hydrogen diselenide exists in the gas mixture.However, hydrogen diselenide can be stable in some solutions.