Calcium sulfide

Crystal structure
	__ Ca 2+ __ S 2−
Crystal system	cubic
Space group	Fm 3 m (No. 225)
Coordination numbers	Ca [6], S [6]
General
Surname	Calcium sulfide
other names	Calcium monosulfide
Ratio formula	CaS
Brief description	colorless to yellowish powder with a smell of hydrogen sulfide
External identifiers / databases
EC number	243-873-5
ECHA InfoCard	100,039,869
PubChem	30182
Wikidata	Q408464
properties
Molar mass	72.14 g mol −1
Physical state	firmly
density	2.8 g cm −3
Melting point	Decomposition> 2000 ° C
solubility	bad in water
safety instructions
H and P phrases	H: 315-319-335-400
	EUH: 031
	P: 261-273-305 + 351 + 338
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Calcium sulfide is a colorless salt consisting of the elements calcium and sulfur with the empirical formula CaS. It crystallizes cubically in the sodium chloride structure .

Occurrence

Calcium sulfide occurs naturally in the form of the rare mineral oldhamite .

Extraction and presentation

It is caused by reduction of calcium sulfate produced by coal

{\ displaystyle \ mathrm {CaSO_ {4} +2 \ C \ longrightarrow \ CaS + 2 \ CO_ {2}}}

and can react further in the reaction mixture to form calcium oxide and sulfur dioxide .

{\ displaystyle \ mathrm {3 \ CaSO_ {4} + \ CaS \ longrightarrow 4 \ CaO + 4 \ SO_ {2}}}

properties

Calcium sulphide is unstable and reacts in contact with water to form calcium hydrogen sulphide (Ca (HS) ₂ ), calcium hydroxide (Ca (OH) ₂ ) and the mixed salt Ca (HS) (OH).

{\ displaystyle \ mathrm {CaS + \ H_ {2} O \ longrightarrow \ Ca (HS) (OH)}}

{\ displaystyle \ mathrm {Ca (HS) (OH) + \ H_ {2} O \ longrightarrow \ Ca (OH) _ {2} + \ H_ {2} S}}

Lime milk Ca (OH) ₂ , when cooked with elemental sulfur, results in "sulfur lime broth", which is used as an insecticide and fungicide . The active substance in this is likely calcium polysulphide, not CaS.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Entry on calcium sulfide in the GESTIS material database of the IFA , accessed on December 29, 2012(JavaScript required) .
↑ Entry on calcium sulphide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1244.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f Entry on calcium sulfide in the GESTIS material database of the IFA , accessed on December 29, 2012(JavaScript required) .

[CLP_100.039.869-2] Entry on calcium sulphide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[3] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1244.