- Barium sulfide
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CASNo = 21109-95-5
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Section2 = Chembox Properties
Formula = BaS
MolarMass = 169.392 g/mol
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MeltingPt = 1200°C
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Autoignition =Barium sulfide is the
chemical compound with the formula BaS. This material was once known as "Bologna Stone", the first syntheticphosphor . Currently thechalcogenide s of the alkaline earth metals are intensely studied as candidates for shortwavelength emitters forelectronic display s. [Vij, D. R.; Singh, N. "Optical and electrical properties of II-VI wide gap semiconducting barium sulfide" Proceedings of SPIE-The International Society for Optical Engineering (1992), 1523(Conf. Phys. Technol. Semicond. Devices Integr. Circuits, 1992), 608-12.] BaS is considered to be the most important synthetic material of barium, being the precursor to BaCO3 and the pigmentlithopone , ZnS/BaSO4. [Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.]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 ofcarbon : [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] :BaSO4 + 2 C → BaS + 2 CO2
BaSO4 is available as the common mineralbarite .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.
afety
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
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