Bisulfide

Bisulfide (systematically named sulfanide and hydrogen(sulfide)(1−)) is an inorganic anion with the chemical formula HS⁻ (also written as SH⁻). It contributes no color to bisulfide salts, and its salts may have a distinctive putrid smell. It is classified as a strong base, bisulfide solutions are corrosive and attack the skin.

Bisulfide is the simplest thiolate. It is an important chemical reagent and industrial chemical, mainly used in textiles, synthetic flavors, coloring brasses, and iron control.

Chemical properties

A variety of salts are known, including sodium hydrosulfide and potassium hydrosulfide. Ammonium hydrosulfide, a component of "stink bombs" has not been isolated as a pure solid. Some compounds described as salts of the sulfide dianion contain primarily hydrosulfide. For example, the hydrated form of sodium sulfide, nominally with the formula Na₂S · 9 H₂O, is better described as NaSH · NaOH · 8 H₂O.

Aqueous bisulfide absorbs light at around 230 nm in the UV/VIS spectrum. Research groups have used field spectrometers to measure the absorption due to bisulfide (and hence its concentration) continuously in the ocean and in sewage. Bisulfide is sometimes confused with the disulfide dianion, S₂²⁻, or ⁻S–S⁻.