Pyrophosphoric acid
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| Pyrophosphoric acid | |
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| General | |
| Systematic name | phosphonooxyphosphonic acid |
| Other names | diphosphoric acid |
| Chemical formula | H4P2O7 |
| SMILES | OP(=O)(O)OP(=O)(O)O |
| Molecular mass | 177.98 g/mol |
| CAS number | 2466-09-3 |
| Properties | |
| Density | ? g/cm³ |
| Melting point | 61 °C |
| Boiling point | ? °C |
| Dissociation constants |
Ka1 = 3 × 10-2 Ka2 = 4.4 × 10-3 Ka3 = 2.5 × 10-7 Ka4 = 5.6 × 10-10 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Pyrophosphoric acid, also known under the name diphosphoric acid, is a syrupy liquid or a needle-like crystalline solid. Pyrophosphoric acid is colorless, odorless, hygroscopic and is soluble in water, diethyl ether, and ethyl alcohol. It is the anhydride of phosphoric acid and is produced from phosphoric acid by dehydration. Pyrophosphoric acid slowly hydrolyzes in the presence of water into phosphoric acid.
- 2H3PO4 ⇌ H4P2O7 + H2O
Pyrophosphoric acid is a medium strong inorganic acid. The anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates.
[edit] See also
- Sodium pyrophosphate
- Calcium pyrophosphate dihydrate deposition disease
- Dimethylallyl pyrophosphate
- ATP
