Potassium pentasulfide is the
inorganic compound with the formula . It is a red-orange solid that dissolves in water. The salt decomposes rapidly in air.
It is one of several
polysulfide
Polysulfides are a class of chemical compounds containing chains of sulfur atoms. There are two main classes of polysulfides: inorganic and organic. Among the inorganic polysulfides, there are ones which contain anions, which have the general formu ...
salts with the general formula , where M = Li, Na, K and ''n'' = 2, 3, 4, 5, 6. The polysulfide salts of potassium and sodium are similar.
Preparation and reactions
The salt is prepared by the addition of elemental sulfur to
potassium sulfide. An idealized equation is shown for potassium hydrosulfide:
:4 + → 2 + 2
The structure consists of zigzag chains of paired with ions.
Occurrence
Various polysulfides - are components of
liver of sulfur
Liver of sulfur is a loosely defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and likely potassium bisulfide. Synonyms include hepar sulfuris, sulfur, sulfurated potash and sulfurated potassa. There are two ...
. Polysulfides, like sulfides, can induce
stress corrosion cracking in
carbon steel and
stainless steel.
References
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Potassium compounds
Polysulfides
Inorganic compounds
Chalcogenides