 | |
 | |
 | |
| Names | |
|---|---|
| IUPAC name Disodium hydrogen phosphate | |
Other names
| |
| Identifiers | |
| |
3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
|
| ECHA InfoCard | 100.028.590 |
| EC Number |
|
| E number | E339(ii)(antioxidants, ...) |
| RTECS number |
|
| UNII |
|
| |
| |
| Properties | |
| Na2HPO4 | |
| Molar mass |
|
| Appearance | White crystalline solid |
| Odor | Odorless |
| Density | 1.7 g/cm3 |
| Melting point | 250 °C (482 °F; 523 K) Decomposes |
| 7.7 g/(100 ml) (20 °C) 11.8 g/(100 ml) (25 °C, heptahydrate) | |
| Solubility | Insoluble inethanol |
| logP | −5.8 |
| Acidity (pKa) | 12.35 |
| −56.6·10−6 cm3/mol | |
Refractive index (nD) | 1.35644 to 1.35717 at 20°C |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Irritant |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 17000 mg/kg (rat, oral) |
| Safety data sheet (SDS) | ICSC 1129 |
| Related compounds | |
Otheranions | sodium phosphite |
Othercations | Dipotassium phosphate Diammonium phosphate |
Related compounds | Monosodium phosphate Trisodium phosphate |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Disodium phosphate (DSP), ordisodium hydrogen phosphate, orsodium phosphate dibasic, is aninorganic compound with thechemical formulaNa2HPO4. It is one of severalsodium phosphates. Thesalt is known inanhydrous form as well ashydratesNa2HPO4·nH2O, wheren is 2, 7, 8, and 12. All are water-soluble white powders. The anhydrous salt ishygroscopic.[1]
ThepH of disodium hydrogen phosphate water solution is between 8.0 and 11.0, meaning it is moderatelybasic:
It can be generated by neutralization ofphosphoric acid withsodium hydroxide:
Industrially It is prepared in a two-step process by treatingdicalcium phosphate withsodium bisulfate, which precipitatescalcium sulfate:[2]
In the second step, the resulting solution of monosodium phosphate is partially neutralized:
It is used in conjunction withtrisodium phosphate in foods and water softening treatment. In foods, it is used to adjust pH. Its presence prevents coagulation in the preparation of condensed milk. Similarly, it is used as an anti-caking additive in powdered products.[3] It is used in desserts and puddings, e.g.Cream of Wheat to quicken cook time, and Jell-OInstant Pudding for thickening. In water treatment, it retardscalcium scale formation.[citation needed] It is also found in some detergents and cleaning agents.[2]
Heating solid disodium phosphate gives the useful compoundtetrasodium pyrophosphate:[citation needed]
Monobasic and dibasic sodium phosphate are used as asaline laxative to treatconstipation or to clean the bowel before acolonoscopy.[4]
Media related toDisodium phosphate at Wikimedia Commons solubility in Prophylaxis alcohol
