Peroxymonosulfuric acid
Powerful oxidizing agent
From Wikipedia, the free encyclopedia
Peroxymonosulfuric acid, also known as persulfuric acid, peroxysulfuric acid is the inorganic compound with the formula H2SO5. It is a white solid. It is a component of Caro's acid, which is a solution of peroxymonosulfuric acid in sulfuric acid containing small amounts of water.[4] Peroxymonosulfuric acid is a very strong oxidant (E0 = +2.51 V).
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| Names | |
|---|---|
| IUPAC names
Peroxysulfuric acid Sulfuroperoxoic acid[1] | |
| Systematic IUPAC name | |
| Other names
Peroxosulfuric acid[1] Peroxomonosulfuric acid[citation needed] Persulfuric acid[citation needed] Caro's acid | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.028.879 |
| EC Number |
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| 101039 | |
PubChem CID |
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| UNII | |
| UN number | 1483 |
CompTox Dashboard (EPA) |
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| Properties | |
| H 2SO 5 | |
| Molar mass | 114.078 g mol−1 |
| Appearance | White crystals[citation needed][dubious – discuss] |
| Density | 2.239 g cm−3 |
| Melting point | 45 °C |
| Acidity (pKa) | 1, 9.3[3] |
| Conjugate base | Peroxomonosulfate |
| Structure | |
| Tetrahedral at S | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
strong oxidizer |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
In peroxymonosulfuric acid, the S(VI) center adopts its characteristic tetrahedral geometry; the connectivity is indicated by the formula HO–O–S(O)2–OH. The S-O-H proton is more acidic.[4]
History
The German chemist Heinrich Caro first reported investigations of mixtures of hydrogen peroxide and sulfuric acid.[5]
Synthesis and production
One laboratory scale preparation of Caro's acid involves the combination of chlorosulfuric acid and hydrogen peroxide:[6]
- H2O2 + ClSO2OH ⇌ H2SO5 + HCl
Patents include more than one reaction for preparation of Caro's acid, usually as an intermediate for the production of potassium monopersulfate (PMPS), a bleaching and oxidizing agent. One route employs the following reaction:[7][better source needed]
- H2O2 + H2SO4 ⇌ H2SO5 + H2O
This reaction occurs in the piranha solution.[8]
Uses in industry
H
2SO
5 and Caro's acid have been used for a variety of disinfectant and cleaning applications, e.g., swimming pool treatment and denture cleaning. It is used in gold mining to destroy the cyanide in the waste stream (tailings).[9]
Alkali metal salts of H
2SO
5, especially oxone, are widely investigated.[10]
Hazards
These peroxy acids can be explosive. Explosions have been reported at Brown University[11] and Sun Oil. As with all strong oxidizing agents, peroxysulfuric acid is incompatible with organic compounds.