Names | |
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Systematic IUPAC name
sulfanide
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Other names
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Identifiers | |
15035-72-0 | |
3D model (Jmol) | Interactive image |
ChEBI | CHEBI:29919 |
ChEMBL | ChEMBL38703 |
ChemSpider | 4224877 |
24766 | |
PubChem | 5047209 |
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Properties | |
HS− |
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Molar mass | 33.07 g·mol−1 |
Acidity (pKa) | >14 |
Basicity (pKb) | <0 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references | |
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.
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, S2−
2, or −S–S−.
The sulfanidyl segment (–S−) in thiolates such as bisulfide can assimilate a proton by recombination:
Because of this capture of a proton (H+), bisulfide has basic character. In aqueous solution, it has a primary pKa value of 6.9. Its conjugate acid is hydrogen sulfide (H2S). However, bisulfide's basicity stems from its behavior as an Arrhenius base. A 1.0 M solution containing spectator-only counter ions, has a basic pH, indicating that most of the bisulfide is unassociated.