Arsenic trisulfide
Names | ||
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Preferred IUPAC name
Arsenic trisulfide | ||
Other names
Arsenic(III) sulfide
Orpiment | ||
Identifiers | ||
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3D model (JSmol)
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ChemSpider | ||
ECHA InfoCard | 100.013.744 | |
EC Number |
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PubChem CID
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RTECS number |
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UNII | ||
CompTox Dashboard (EPA)
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Properties | ||
As2S3 | ||
Molar mass | 246.02 g·mol−1 | |
Appearance | Orange crystals | |
Density | 3.43 g cm−3 | |
Melting point | 310 °C (590 °F; 583 K) | |
Boiling point | 707 °C (1,305 °F; 980 K) | |
-70.0·10−6 cm3/mol | ||
Structure[1] | ||
P21/n (No. 11) | ||
a = 1147.5(5) pm
, b = 957.7(4) pm , c = 425.6(2) pmα = 90°, β = 90.68(8)°, γ = 90°
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pyramidal (As) | ||
Hazards | ||
NFPA 704 |
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U.S. Permissible exposure limit (PEL) |
[1910.1018] TWA 0.010 mg/m3 | |
Related compounds | ||
Other anions | Arsenic trioxide Arsenic triselenide | |
Other cations | Phosphorus trisulfide Antimony trisulfide Bismuth sulfide | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | ||
verify (what is ?) | ||
Infobox references | ||
Arsenic trisulfide, also known as orpiment or arsenic(III) sulfide, is a chemical compound. Its chemical formula is As2S3. It has arsenic and sulfide ions in it. The arsenic is in its +3 oxidation state.
Properties[change | change source]
Arsenic trisulfide is a yellow solid. It is a semiconductor. It has a glass (amorphous) form and a crystalline form. It burns in air to make sulfur dioxide and arsenic trioxide, which makes a highly toxic smoke. Arsenic trisulfide can oxidize on the surface to make a highly toxic layer of arsenic trioxide as well. Arsenic trisulfide is not toxic unless it oxidizes. It does not react with acids.
Occurrence[change | change source]
Arsenic trisulfide is found as the mineral orpiment.
Preparation[change | change source]
Arsenic trisulfide is made when an arsenic compound like arsenic trichloride reacts with hydrogen sulfide. It is also made when arsenic and sulfur are heated together.
Uses[change | change source]
It was looked at for treating cancer. It was used by the Egyptians as a pigment and cosmetic. It is used in glass.
References[change | change source]
- ↑ Mullen, D. J. E.; Nowacki, W (1972), "Refinement of the crystal structures of realgar, AsS and orpiment, As2S3" (PDF), Z. Kristallogr., 136 (1–2): 48–65, doi:10.1524/zkri.1972.136.1-2.48.