Peroxodisulfuric acid
| Structural formula | ||||||||||
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| General | ||||||||||
| Surname | Peroxodisulfuric acid | |||||||||
| other names |
Marshallic acid |
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| Molecular formula | H 2 S 2 O 8 | |||||||||
| Brief description |
white, inconsistent crystals |
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| properties | ||||||||||
| Molar mass | 194.15 g mol −1 | |||||||||
| Physical state |
firmly |
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| Melting point |
60 ° C |
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| safety instructions | ||||||||||
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||
Peroxodisulfuric acid is an oxo acid of sulfur (Marshall's acid). It forms white crystals that are soluble in water. Peroxodisulfuric acid has a strong oxidizing effect. It is used, for example, for the production of hydrogen peroxide (via hydrolysis ), for hydroxylation of phenols and as a pickling solution for the surface treatment of metals . Its salts, the peroxodisulphates , are much more stable than the acid and are used as strong oxidizing agents.
synthesis
The production of peroxodisulfuric acid in solution takes place technically via electrolysis of an approx. 50% sulfuric acid solution at a high current density . In the laboratory, the same reaction that leads to peroxomonosulfuric acid with an excess of chlorosulfonic acid is used for pure preparation .
Individual evidence
- ↑ a b c Entry on peroxodisulfuric acid. In: Römpp Online . Georg Thieme Verlag, accessed on June 13, 2014.
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ↑ G. Brauer (Ed.): Handbook of Preparative Inorganic Chemistry 2nd ed., Vol. 1, Academic Press 1963, pp. 389-390.