Names | |
---|---|
IUPAC name
dipotassium (sulfonatooxy)sulfonate
| |
Other names
Potassium pyrosulphate; potassium disulfate
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.029.288 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
K2O7S2 | |
Molar mass | 254.31 g·mol−1 |
Density | 2.28 g/cm3 |
Melting point | 325 °C (617 °F; 598 K) |
25.4 g/100 mL (20 °C) | |
Hazards | |
GHS labelling: | |
Danger | |
H314, H331 | |
P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P321, P363, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Potassium pyrosulfate, or potassium disulfate, is an inorganic compound with the chemical formula K2S2O7.
Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from potassium bisulfate: [1]
Temperatures above 600°C further decompose potassium pyrosulfate to potassium sulfate and sulfur trioxide however: [2]
Other salts, such as potassium trisulfate, [3] can also decompose into potassium pyrosulfate.
Potassium pyrosulfate contains the pyrosulfate anion which has a dichromate-like structure. The geometry can be visualized as a tetrahedron with two corners sharing the SO4 anion's configuration and a centrally bridged oxygen atom. [4] A semi- structural formula for the pyrosulfate anion is O3SOSO32−. The oxidation state of sulfur in this compound is +6.
Potassium pyrosulfate is used in analytical chemistry; samples are fused with potassium pyrosulfate, (or a mixture of potassium pyrosulfate and potassium fluoride) to ensure complete dissolution prior to a quantitative analysis. [5] [6]
The compound is also present in a catalyst in conjunction with vanadium(V) oxide in the industrial production of sulfur trioxide. [7]
Potassium disulfate.
Potassium disulfate.