Sulfide
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Systematic IUPAC name | |||
Identifiers | |||
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Properties | |||
S2− | |||
Molar mass | 32.06 g·mol−1 | ||
Conjugate acid
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Bisulfide | ||
Related compounds | |||
Other anions
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oxide selenide Telluride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sulfide (
(SH−) are the conjugate acids of sulfide.Chemical properties
The sulfide ion, S2−, does not exist in aqueous alkaline solutions of Na2S.[3][4] Instead sulfide converts to hydrosulfide:
- S2− + H2O → SH− + OH−
Upon treatment with an acid, sulfide salts convert to hydrogen sulfide:
- S2− + H+ → SH−
- SH− + H+ → H2S
Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts.
- 8 MgS + 8 I2 → S8 + 8 MgI2
Metal derivatives
Aqueous solutions of
Geology
Many important metal ores are sulfides.[6] Significant examples include: argentite (silver sulfide), cinnabar (mercury sulfide), galena (lead sulfide), molybdenite (molybdenum sulfide), pentlandite (nickel sulfide), realgar (arsenic sulfide), and stibnite (antimony), sphalerite (zinc sulfide), and pyrite (iron disulfide), and chalcopyrite (iron-copper sulfide). This sulfide minerals recorded information (like isotopes) of their surrounding environment during their formation. Scientists use these minerals to study environments in the deep sea or in the Earth's past.[7]
Corrosion induced by sulfide
Dissolved free sulfides (H2S, HS− and S2−) are very aggressive species for the corrosion of many metals such as steel, stainless steel, and copper. Sulfides present in aqueous solution are responsible for stress corrosion cracking (SCC) of steel, and is also known as sulfide stress cracking. Corrosion is a major concern in many industrial installations processing sulfides: sulfide ore mills, deep oil wells, pipelines transporting soured oil and Kraft paper factories.
Oxidation of sulfide can also form thiosulfate (S
2O2−
3) an intermediate species responsible for severe problems of pitting corrosion of steel and stainless steel while the medium is also acidified by the production of sulfuric acid when oxidation is more advanced.
Organic chemistry
In
Disulfides
Confusion arises from the different meanings of the term "
Examples
Formula | Melting point (°C) | Boiling point (°C) | CAS number | |
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H2S | Hydrogen sulfide is a very toxic and corrosive gas characterised by a typical odour of "rotten egg". | −85.7 | −60.20 | 7783-06-4 |
CdS | photocells . |
1750 | 1306-23-6 | |
Calcium polysulfide ("lime sulfur") is a traditional fungicide in gardening. | ||||
CS2 | Carbon disulfide is a precursor to organosulfur compounds. | −111.6 | 46 | 75-15-0 |
PbS | infra-red sensors. |
1114 | 1314-87-0 | |
MoS2 | Molybdenum disulfide, the mineral molybdenite, is used as a catalyst to remove sulfur from fossil fuels; also as lubricant for high-temperature and high-pressure applications. | 1317-33-5 | ||
Cl–CH2CH2–S–CH2CH2–Cl | organosulfur compound (thioether) that was used as a chemical weapon in the First World War. |
13–14 | 217 | 505-60-2 |
Ag2S | Silver sulfide is a component of silver tarnish. | 21548-73-2 | ||
Na2S | organosulfur compounds . |
920 | 1180 | 1313-82-2 |
ZnS | lenses and other optical devices in the infrared part of the spectrum. ZnS-doped with silver is used in alpha detectors while zinc sulfide with traces of copper has applications in photoluminescent strips for emergency lighting and luminous watch dials. |
1850 | 1314-98-3 | |
C6H4S | Polyphenylene sulfide is a polymer commonly called "Sulfar". Its repeating units are bonded together by sulfide (thioether) linkages. | 26125-40-6 25212-74-2 | ||
SeS2 | antifungal used in anti-dandruff preparations, such as Selsun Blue . The presence of the highly toxic selenium in healthcare and cosmetics products represents a general health and environmental concern. |
<100 | 7488-56-4 | |
FeS2 | Known as "fool's gold", pyrite, is a common mineral. | 600 | 1317-66-4 |
Preparation
Sulfide compounds can be prepared in several different ways:[8]
- Direct combination of elements:
- Example: Fe(s) + S(s) → FeS(s)
- Reduction of a sulfate:
- Example: MgSO4(s) + 4C(s) → MgS(s) + 4CO(g)
- Precipitation of an insoluble sulfide:
- Example: M2+ + H2S(g) → MS(s) + 2H+(aq)
Safety
Many metal sulfides are so insoluble in water that they are probably not very toxic. Some metal sulfides, when exposed to a strong mineral acid, including gastric acids, will release toxic hydrogen sulfide.
Organic sulfides are highly flammable. When a sulfide burns it produces sulfur dioxide (SO2) gas.
Hydrogen sulfide, some of its salts, and almost all organic sulfides have a strong and putrid stench; rotting biomass releases these.
Nomenclature
The systematic names sulfanediide and sulfide(2−), valid IUPAC names, are determined according to the substitutive and additive nomenclatures, respectively. However, the name sulfide is also used in compositional IUPAC nomenclature which does not take the nature of bonding involved. Examples of such naming include selenium disulfide and titanium sulfide, which contain no sulfide ions.
References
- ^ a b "sulfide(2−) (CHEBI:15138)". Chemical Entities of Biological Interest (ChEBI). UK: European Bioinformatics Institute.
- ^ "SULFIDE English Definition and Meaning". Lexico.com. Archived from the original on August 2, 2019. Retrieved 2022-08-24.
- PMID 29404555.
- .
- ISBN 9780470050583.
- ISBN 0-521-21489-0.
- ISSN 2296-6846.
- ^ Atkins; Shriver (2010). Inorganic Chemistry (5th ed.). New York: W. H. Freeman & Co. p. 413.
External links
- Media related to Sulfides at Wikimedia Commons