It is the chemical compound with the formula Na2S, or more chemical the hydrate Na2S9H2O. Both are water-soluble colorless sales that give strongly alkaline solutions. When exposed to moist air, Na2S and its hydrates emit hydrogen sulfide, which tastes like rotten eggs.


Sulphides are combinations of compounds that are formed from sulfur, with an oxidation state, together with another chemical element or even, together with a radical. There are sulfur compounds, of the covalent type, which are also considered sulphides, as in the case of hydrogen sulphide, being this one of the most important compounds of this type. Most sulphides are toxic to humans, both by inhalation and by ingestion, especially if the combined metal ion is toxic.