Iron(II) sulfide
2091630
209107716
2008-04-29T22:55:32Z
Dasein45
7003186
added a "biology and biochemical uses" section
{{Chembox new
| Name = Iron(II) sulfide
| ImageFile = Iron(II)-sulfide-sample.jpg
<!-- | ImageSize = 200px -->
| ImageName = Sample of iron(II) sulfide
| ImageFile1 = Iron(II)-sulfide-unit-cell-3D-balls.png
<!-- | ImageSize1 = 150px -->
| ImageName1 = Ball-and-stick model of FeS's unit cell
| OtherNames = Iron sulfide<br />Iron sulphide
| Section1 = {{Chembox Identifiers
| CASNo = 12068-85-8
}}
| Section2 = {{Chembox Properties
| Formula = FeS
| MolarMass = 87.911 g/mol
| Density = 4.84 g/cm<sup>3</sup>
| Solvent = other solvents
| SolubleOther = insoluble
| MeltingPt = 1194 °C
| BoilingPt =
| Appearance = black solid}}
}}
'''Iron(II) sulfide''' is a [[chemical compound]] with the formula FeS. In practice, iron sulfides are often non-[[stoichiometric]]. Powdered iron sulfide is [[pyrophoric]].
FeS can be obtained by reacting [[iron]] and [[sulfur]].
:S<sub>8 (s)</sub> + 8Fe<sub>(s)</sub> → 8FeS<sub>(s)</sub>
==Forms of iron sulfide==
"Iron sulfide" exists in several distinct forms which differ in the [[stoichiometry]] and properties:
*[[Pyrrhotite]], Fe<sub>1-x</sub>S, a mineral as well as the waste product of the ''[[Desulfovibrionales|Desulfovibrio]]'' bacteria, pyrrhotite displays [[ferrimagnetism]].
*[[Troilite]], FeS, which has similar material to pyrrhotite, but does not possess [[ferromagnetic]] properties.
*[[Mackinawite]], Fe<sub>1+x</sub>S, the least stable from of iron sulfide, mackinawite has a layered structure.
*[[Pyrite]], mineral form of FeS<sub>2</sub> with a [[gold]]-like appearance, making it also known as "fool's gold."
==Pedagogical uses==
Certain chemical principles are nicely illustrated using the chemistry of iron sulfides.
The methods of [[chemical composition]] can be shown by the production of iron(II) sulfide from [[iron]] and [[sulfur]] (see equation above).
*This reaction is [[exothermic]] as more energy is given out than taken in.
*Iron shows [[ferromagnetism]]; iron sulfides do not.
*Iron sulfide with [[hydrochloric acid]] (HCl), the [[acidic]] [[properties]] of hydrochloric acid and the pungent fume of [[hydrogen sulfide]] can both be demonstrated:
:FeS<sub>(s)</sub> + 2HCl<sub>(aq)</sub> → FeCl<sub>2 (aq)</sub> + H<sub>2</sub>S<sub>(g)</sub>
==Biological and biochemical uses==
The presence of ferrous sulfide as a visible black precipitate in the [[growth medium|growth medium]] [[peptone]] iron agar can be used to distinguish between [[microorganisms]] that produce the [[cysteine metabolism|cysteine metabolizing]] enzyme [[D-cysteine desulfhydrase|cysteine desulfhydrase]] and those that do not. Peptone iron agar contains the [[amino acid]] [[cysteine]] and a chemical indicator, [[ferric citrate]]. The [[catalysis]] of cysteine releases [[hydrogen sulfide]] gas that reacts with the ferric citrate to produce ferrous sulfide.
==See also==
* [[Iron-sulfur world theory]]
==References==
{{Citationstyle|date=September 2007}}
<references/>
*D. Vaughan, J. Craig, (1978) ''Mineral Chemistry of Metal Sulfides'', Cambridge University Press. ISBN 0-521-21489-0
[[Category:Iron compounds]]
[[Category:Sulfides]]
[[ar:كبريتيد حديد ثنائي]]
[[de:Eisen(II)-sulfid]]
[[ja:硫化鉄(II)]]
[[pl:Siarczek żelaza(II)]]
[[pt:Sulfeto de ferro]]