Disodium pyrophosphate
| Names | |
|---|---|
| IUPAC name
Disodium dihydrogen diphosphate | |
| Other names
Diphosphoric acid, disodium salt Disodium dihydrogen pyrophosphate Disodium diphosphate Sodium acid pyrophosphate, SAPP | |
| Identifiers | |
3D model (JSmol) |
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| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.028.941 |
| EC Number |
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| E number | E450(i) (thickeners, ...) |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| Na2H2P2O7 | |
| Molar mass | 221.936 g·mol−1 |
| Appearance | White odorless powder |
| Density | 2.31 g/cm3 |
| Melting point | > 600 °C |
| 11.9 g/(100 mL) (20 °C) | |
Refractive index (nD) |
1.4645 (hexahydrate) |
| Hazards | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
2650 mg/kg (mouse, oral) |
| Related compounds | |
Other anions |
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Other cations |
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Related compounds |
Tetrasodium pyrophosphate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Disodium pyrophosphate or sodium acid pyrophosphate (SAPP) is an inorganic compound with the chemical formula Na2H2P2O7. It consists of sodium cations (Na+) and dihydrogen pyrophosphate anions (H2P2O2−7). It is a white, water-soluble solid that serves as a buffering and chelating agent, with many applications in the food industry. When crystallized from water, it forms a hexahydrate, but it dehydrates above room temperature. Pyrophosphate is a polyvalent anion with a high affinity for polyvalent cations, e.g. Ca2+.
Disodium pyrophosphate is produced by heating sodium dihydrogen phosphate:
- 2 NaH2PO4 → Na2H2P2O7 + H2O