Disulfuric acid


Disulfuric acid
Disulfuric acid
Identifiers
CAS number 7783-05-3 YesY
PubChem 62682
ChemSpider 56433 YesY
EC number 231-976-8
MeSH Pyrosulfuric+acid
ChEBI CHEBI:29211 YesY
Jmol-3D images Image 1
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Properties
Molecular formula H2O7S2
Molar mass 178.14 g mol−1
Exact mass 177.924193798 g mol-1
Melting point

36 °C, 309 K, 97 °F

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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Disulfuric acid is an oxoacid of sulfur. It is a major constituent of fuming sulfuric acid, oleum, and this is how most chemists encounter it. It is also a minor constituent of liquid anhydrous sulfuric acid due to the equilibria:

H2SO4 H2O + SO3
SO3 + H2SO4 H2S2O7

The acid is prepared by reacting excess SO3 with sulfuric acid:

H2SO4 + SO3 → H2S2O7

Disulfuric acid can be seen as the sulfuric acid analogue of an acid anhydride. The mutual electron-withdrawing effects of each sulfuric acid unit on its neighbour causes a marked increase in acidity. Disulfuric acid is strong enough to protonate "normal" sulfuric acid in the (anhydrous) sulfuric acid solvent system. There are salts of disulfuric acid, commonly called pyrosulfates, e.g. potassium pyrosulfate.

There are other related acids with the general formula H2O.(SO3)x though none are isolable.

See also

References

Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 


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Look at other dictionaries:

  • disulfuric acid — [dī΄sul fyoor′ik] n. PYROSULFURIC ACID * * * …   Universalium

  • disulfuric acid — [dī΄sul fyoor′ik] n. PYROSULFURIC ACID …   English World dictionary

  • disulfuric acid — pirosieros rūgštis statusas T sritis chemija formulė H₂S₂O₇ atitikmenys: angl. disulfuric acid; pyrosulfuric acid rus. дисерная кислота; пиросерная кислота ryšiai: sinonimas – disulfato rūgštis sinonimas – vandenilio μ okso( )heksaoksodisulfatas… …   Chemijos terminų aiškinamasis žodynas

  • disulfuric acid — (|)dī+... noun Etymology: di + sulfuric : pyrosulfuric acid …   Useful english dictionary

  • Peroxymonosulfuric acid — Chembox new Name = Peroxymonosulfuric acid ImageFile = Peroxymonosulfuric acid.svg ImageFile1 = Caro s acid 3D balls.png ImageName1 = Ball and stick model of peroxymonosulfuric acid OtherNames = persulfuric acid, peroxysulfuric acid,… …   Wikipedia

  • pyrosulfuric acid — “+... noun Etymology: International Scientific Vocabulary pyr + sulfuric : an unstable, crystalline acid H2S2O7 that is usually handled commercially as a thick oily fuming liquid, that is formed by the union of sulfur trioxide with sulfuric acid …   Useful english dictionary

  • py|ro|sul|fu|ric acid — «PY roh suhl FYUR ihk, PIHR oh », a thick, fuming liquid acid, a powerful oxidizing and dehydrating agent; disulfuric acid. Formula: H2S2O7 …   Useful english dictionary

  • disulphuric acid — /ˌdaɪsʌlfjʊərɪk ˈæsəd/ (say .duysulfyoouhrik asuhd) noun → fuming sulphuric acid. Also, disulfuric acid …   Australian English dictionary

  • pyrosulfuric acid — pirosieros rūgštis statusas T sritis chemija formulė H₂S₂O₇ atitikmenys: angl. disulfuric acid; pyrosulfuric acid rus. дисерная кислота; пиросерная кислота ryšiai: sinonimas – disulfato rūgštis sinonimas – vandenilio μ okso( )heksaoksodisulfatas… …   Chemijos terminų aiškinamasis žodynas

  • peroxydisulfuric acid — “+... noun Etymology: peroxy + disulfuric : persulfuric acid a * * * /peuh rok see duy sul fyoor ik, rok /, Chem. See persulfuric acid (def. 2). [PEROXY + DI 1 + SULFURIC ACID] …   Useful english dictionary


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