Calcium sulfide

Calcium sulfide
Calcium sulfide
Names
IUPAC name
Calcium sulfide
Other names
Calcium monosulfide,
Hepar calcies,
Sulfurated lime
Oldhamite
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.039.869 Edit this at Wikidata
EC Number
  • 243-873-5
KEGG
UNII
  • InChI=1S/Ca.S/q+2;-2 checkY
    Key: AGVJBLHVMNHENQ-UHFFFAOYSA-N checkY
  • InChI=1/Ca.S/rCaS/c1-2
    Key: JGIATAMCQXIDNZ-WSLZQIQFAE
  • InChI=1/Ca.S/q+2;-2
    Key: AGVJBLHVMNHENQ-UHFFFAOYAE
  • [Ca]=S
  • [Ca+2].[S-2]
Properties
CaS
Molar mass 72.143 g/mol
Appearance white crystals
hygroscopic
Density 2.59 g/cm3
Melting point 2,525 °C (4,577 °F; 2,798 K)
Hydrolyses
Solubility Insoluble in alcohol
reacts with acid
2.137
Structure
Halite (cubic), cF8
Fm3m, No. 225
Octahedral (Ca2+); octahedral (S2−)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Reacts with water to release H2S
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation markGHS09: Environmental hazard
Warning
H315, H319, H335, H400
P261, P273, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
2
0
3
Related compounds
Other anions
 Calcium oxide
Other cations
 Magnesium sulfide
Strontium sulfide
Barium sulfide
Related sulfides
 Sodium sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Calcium sulfide is the chemical compound with the formula CaS. This white material crystallizes in cubes like rock salt. CaS has been studied as a component in a process that would recycle gypsum, a product of flue-gas desulfurization. Like many salts containing sulfide ions, CaS typically has an odour of H2S, which results from small amount of this gas formed by hydrolysis of the salt.

In terms of its atomic structure, CaS crystallizes in the same motif as sodium chloride indicating that the bonding in this material is highly ionic. The high melting point is also consistent with its description as an ionic solid. In the crystal, each S2− ion is surrounded by an octahedron of six Ca2+ ions, and complementarily, each Ca2+ ion surrounded by six S2− ions.