Potassium pyrosulfate

Production

Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from potassium bisulfate: : 2 KHSO4 → K2S2O7 + H2O Temperatures above 600°C further decompose potassium pyrosulfate to potassium sulfate and sulfur trioxide however: : K2S2O7 → K2SO4 + SO3

Other salts, such as potassium trisulfate, can also decompose into potassium pyrosulfate.

Chemical structure

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. A semi-structural formula for the pyrosulfate anion is O3SOSO32−. The oxidation state of sulfur in this compound is +6.

Uses

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.

The compound is also present in a catalyst in conjunction with vanadium(V) oxide in the industrial production of sulfur trioxide.

References

References

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