Barium sulfide
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3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.040.180 |
| EC Number |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| BaS | |
| Molar mass | 169.39 g/mol |
| Density | 4.25 g/cm3 [1] |
| Melting point | 1200 °C |
| Boiling point | decomposes |
| 2.88 g/cm3 (0 °C) 7.68 g/cm3 (20 °C) 60.3 g/100 mL (100 °C) | |
| Solubility | insoluble in alcohol |
Refractive index (nD)
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2.155 |
| Structure | |
| Halite (cubic), cF8 | |
| Fm3m, No. 225 | |
| Octahedral (Ba2+); octahedral (S2–) | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Other anions
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Barium oxide |
Other cations
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Magnesium sulfide Calcium sulfide Strontium sulfide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Barium sulfide is the chemical compound with the formula BaS. Currently the chalcogenides of the alkaline earth metals are intensely studied as candidates for short wavelength emitters for electronic displays.[2] BaS is considered to be the most important synthetic material of barium, being the precursor to BaCO3 and the pigment lithopone, ZnS/BaSO4.[3]
Discovery, production, properties
The BaS was prepared by Vincentius (or Vincentinus) Casciarolus (or Casciorolus, 1571-1624) via a crude version of what is now known as a "carbothermic reduction", employing flour in place of carbon:[4]
- BaSO4 + 2 C → BaS + 2 CO2
The phosphorescence of the substance made the material a curiosity and various alchemists and chemists made experiments with the material which was known as Lapis Boloniensis, Chrysolapis or bologna stone.[5][6][7]
Andreas Sigismund Marggraf showed that calcite and gypsum were not very suitable for the production of the bologna stone, but a special heavy fluorspar, in the end he concluded that calcium sulfate is the material from which the bologna stone is made.[8]
BaSO4 is available as the common mineral barite.
BaS, m.p. 1200 °C, crystallizes with the NaCl structure and is currently manufactured by an improved version of Casciarolus's route: using coke in place of flour. It is colorless, although like many sulfides, it is commonly obtained in impure colored forms.
Safety
BaS is quite poisonous, as are related sulfides, such as CaS, which evolve toxic hydrogen sulfide upon contact with water. The particular problem with BaS is that its name resembles that of the insoluble, non-toxic material given in large doses to some medical patients. Switching BaS for BaSO4 is lethal.
References
- ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
- ^ Vij, D. R.; Singh, N. "Optical and electrical properties of II-VI wide gap semiconducting barium sulfide" Proceedings of SPIE (1992), 1523 (Conf. Phys. Technol. Semicond. Devices Integr. Circuits, 1992), 608-12.
- ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
- ^ F. Licetus, Litheosphorus, sive de lapide Bononiensi lucem in se conceptam ab ambiente claro mox in tenebris mire conservante, Utini, ex typ. N. Schiratti, 1640. See http://www.chem.leeds.ac.uk/delights/texts/Demonstration_21.htm
- ^ "Lapis Boloniensis". www.zeno.org.
- ^ Lemery, Nicolas (1714). Trait℗e universel des drogues simples.
- ^ Ozanam, Jacques; Montucla, Jean Etienne; Hutton, Charles (1814). Recreations in mathematics and natural philosophy .
- ^ Marggraf, Andreas Sigismund (1767). Chymische Schriften.