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 |
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PubChem CID
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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) pm α = 90°, β = 90.68(8)°, γ = 90°
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| pyramidal (As) | |
| Hazards | |
| NFPA 704 |
0
3
0
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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   ?)
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| 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.