Potassium pyrosulfate, or potassium disulfate, is an inorganic compound with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

K₂S₂O₇.

Production

Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from

potassium bisulfate Potassium bisulfate/ Potassium Sulphate is an inorganic compound with the chemical formula KHSO4 and is the potassium acid salt of sulfuric acid. It is a white, water-soluble solid. Preparation More than 1 million tons were produced in 1985 a ...

: : 2 KHSO₄ → K₂S₂O₇ + H₂O Temperatures above 600°C further decompose potassium pyrosulfate to

potassium sulfate Potassium sulfate (US) or potassium sulphate (UK), also called sulphate of potash (SOP), arcanite, or archaically potash of sulfur, is the inorganic compound with formula K2SO4, a white water-soluble solid. It is commonly used in fertilizers, prov ...

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 In chemistry, disulfate or pyrosulfate is the anion with the molecular formula . Disulfate is the IUPAC name. It has a dichromate-like structure and can be visualised as two corner-sharing SO4 tetrahedra, with a bridging oxygen atom. In this a ...

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

which has a dichromate-like structure. The

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...

can be visualized as a

tetrahedron In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all th ...

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 In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...

of sulfur in this compound is +6.

Uses

Potassium pyrosulfate is used in

analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...

; samples are fused with potassium pyrosulfate, (or a mixture of potassium pyrosulfate and

potassium fluoride Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide and occurs naturally as the rare ...

) to ensure complete dissolution prior to a quantitative analysis. The compound is also present in a

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

in conjunction with

vanadium(V) oxide Vanadium(V) oxide (''vanadia'') is the inorganic compound with the formula V2 O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because ...

in the industrial production of sulfur trioxide.

References

{{Potassium compounds Potassium compounds Pyrosulfates

Production

Chemical structure

Uses

See also

References