Disodium Phosphate CAS#7558-79-4
High Solubility: Disodium phosphate has good solubility in water, insoluble in ethanol. Its aqueous solution shows weak alkalinity, which supports wide applications in food processing, water treatment and chemical industries.
Stable Performance: Anhydrous disodium phosphate is relatively stable at room temperature; the hydrated form will lose crystal water when heated. It maintains stable properties in neutral and weak alkaline aqueous systems.
Versatile Uses: It is widely used as food pH regulator, water treatment softener, analytical reagent, and raw material for phosphate production.
Crystalline Form & Hygroscopic Nature: This material is supplied as white crystalline powder or granular solid. The anhydrous grade is slightly hygroscopic, and sealed packaging is required to prevent moisture absorption.
Disodium phosphate, characterized by the molecular formula Na₂HPO₄, presents as a white crystalline powder or granule with slight hygroscopic properties. It exhibits good solubility in water (77 g/L at 20°C), insoluble in ethanol. A 10% aqueous solution of this compound maintains a pH range of 8.0–9.0, showing good stability under normal temperature. The substance may cause mild irritation to eyes, skin and respiratory tract, and it is utilized for food buffering agent, water softener, analytical reagent and raw material for sodium phosphate series products.
Disodium Phosphate Chemical Properties
| Item | Specification |
|---|---|
| Melting point | 250 °C (dec.)(lit.) |
| Density | 1.7 g/cm³ (anhydrous) |
| Refractive index | 1.463 |
| Storage temp | Store below +30°C, keep sealed |
| Solubility | Water: 77 g/L (20°C); insoluble in ethanol |
| Form | Crystalline powder / granule |
| Color | White |
| Odor | Odorless |
| PH Range | 8.0–9.0 (10% aqueous solution, 20℃) |
| Water Solubility | 77 g/L (20 º C) |
| Sensitive | Slightly hygroscopic |
| Stability | Stable. Incompatible with strong acids |
| CAS DataBase Reference | 7558-79-4 (CAS DataBase Reference) |
| NIST Chemistry Reference | Disodium phosphate (7558-79-4) |
| EPA Substance Registry System | Disodium hydrogen phosphate (7558-79-4) |
Safety Information
| Item | Specification |
|---|---|
| Hazard Codes | Xi |
| Risk Statements | 36/37/38 |
| Safety Statements | 26-36 |
| WGK Germany | 1 |
| RTECS | WB0360000 |
| TSCA | Yes |
| HS Code | 28352200 |
This compound is employed as a pH buffering agent in food industry, a water softener for boiler water treatment, and a raw material for preparing other phosphate salts. It also functions as a culture medium component in biochemical research, an additive in detergents, and an auxiliary agent in textile printing and dyeing. Additionally, it finds application in feed additives and ceramic glaze processing.
