 | |
| Identifiers | |
|---|---|
3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
|
| ECHA InfoCard | 100.040.180 |
| EC Number |
|
| 13627 | |
| UNII | |
| |
| |
| Properties | |
| BaS | |
| Molar mass | 169.39 g/mol |
| Appearance | white solid |
| Density | 4.25 g/cm3[1] |
| Melting point | 2,235[2] °C (4,055 °F; 2,508 K) |
| Boiling point | decomposes |
| 2.88 g/100 mL (0 °C) 7.68 g/100 mL (20 °C) 60.3 g/100 mL (100 °C) (reacts) | |
| Solubility | insoluble in alcohol |
Refractive index (nD) | 2.155 |
| Structure | |
| Halite (cubic),cF8 | |
| Fm3m, No. 225 | |
| Octahedral (Ba2+); octahedral (S2−) | |
| Hazards | |
| GHS labelling: | |
  | |
| Warning | |
| H315,H319,H335,H400 | |
| P261,P264,P271,P273,P280,P302+P352,P304+P340,P305+P351+P338,P312,P321,P332+P313,P337+P313,P362,P391,P403+P233,P405,P501 | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 226 mg/kg humans |
| Related compounds | |
Otheranions | Barium oxide Barium selenide Barium telluride Barium polonide |
Othercations | Beryllium sulfide Magnesium sulfide Calcium sulfide Strontium sulfide Radium sulfide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Barium sulfide is theinorganic compound with the formulaBaS. BaS is the barium compound produced on the largest scale.[3] It is an important precursor to other barium compounds includingbarium carbonate and the pigmentlithopone, ZnS/BaSO4.[4] Like otherchalcogenides of the alkaline earth metals, BaS is a shortwavelength emitter forelectronic displays.[5] It is colorless, although like many sulfides, it is commonly obtained in impure colored forms.
BaS was prepared by the Italian alchemist Vincenzo Cascariolo (also known as Vincentius or Vincentinus Casciarolus or Casciorolus, 1571–1624) via the thermo-chemical reduction ofBaSO4 (available as the mineralbarite).[6] It is currently manufactured by an improved version of Cascariolo's process usingcoke in place of flour andcharcoal. This kind of conversion is called acarbothermic reaction:
and also:
The basic method remains in use today. BaS dissolves in water. These aqueous solutions, when treated withsodium carbonate orcarbon dioxide, give a white solid ofbarium carbonate, a source material for many commercial barium compounds.[7]
According to Harvey (1957),[8] in 1603, Vincenzo Cascariolo usedbarite, found at the bottom of Mount Paterno nearBologna, in one of his non-fruitful attempts to producegold. After grinding and heating the mineral with charcoal under reducing conditions, he obtained a persistentluminescent material that soon came to be known asLapis Boloniensis, or Bolognian stone.[9][10] Thephosphorescence of the material obtained by Casciarolo made it a curiosity.[11][12][13]
A modern procedure proceeds from barium carbonate:[14]
BaS crystallizes with theNaCl structure, featuring octahedral Ba2+ and S2− centres.
The observedmelting point of barium sulfide is highly sensitive to impurities.[2]
BaS is quite poisonous, as are related sulfides, such as CaS, which evolve toxichydrogen sulfide upon contact with water. Barium itself is also toxic.
