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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CompTox Dashboard (EPA)
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SMILES
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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] | ||
Space group
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P21/n (No. 11) | |
Lattice constant
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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 | {{{value}}} | |
| Other cations | {{{value}}} | |
| Related compounds | {{{value}}} | |
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
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
Arsenic trisulfide is found as the mineral orpiment.
Preparation
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
It was looked at for treating cancer. It was used by the Egyptians as a pigment and cosmetic. It is used in glass.
References
- ↑ 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.