Sodium Phosphate, Dibasic Chemical Properties

Melting point:

243-245 °C

Density 

1.064 g/mL at 20 °C

vapor density 

4.9 (vs air)

vapor pressure 

0Pa at 20℃

FEMA 

2398 | DISODIUM PHOSPHATE

storage temp. 

Store at +5°C to +30°C.

solubility 

H₂O: 0.5 M at 20 °C, clear, colorless

form 

powder

color 

White

PH

8.9-9.2 (25℃, 50g/L in water)

pka

(1) 2.15, (2) 6.82, (3) 12.38 (at 25℃)

Odor

odorless

Water Solubility 

>=10 g/100 mL at 20 ºC

Sensitive 

Hygroscopic

λmax

λ: 260 nm Amax: 0.019
λ: 280 nm Amax: 0.016

Merck 

14,8659

Stability:

Stable. Incompatible with strong acids. Hygroscopic.

InChIKey

BNIILDVGGAEEIG-UHFFFAOYSA-L

LogP

-2.15

CAS DataBase Reference

7558-79-4(CAS DataBase Reference)

EPA Substance Registry System

Disodium phosphate (7558-79-4)

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36-24/25

RIDADR 

UN 3077 9 / PGIII

WGK Germany 

3

RTECS 

WC4500000

F 

3

TSCA 

Yes

HS Code 

28352200

Hazardous Substances Data

7558-79-4(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: > 2000 mg/kg

MSDS

• Language:English Provider:Disodium hydrogenorthophosphate
• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Sodium Phosphate, Dibasic Usage And Synthesis

Description

Sodium phosphate dibasic is highly hygroscopic and water soluble. Useful in conjunction with Sodium Phosphate, Monobasic in the preparation of biological buffers. It is commonly used in biological assay buffers. Sodium is required for nerve and muscle functioning. Sodium Phosphate Dibasic can be used as a dietary supplement and as a nutrient. Sodium hydrogen phosphate is used in food and water treatment in conjunction with trisodium phosphate.In foods, it is used to adjust pH. In water treatment, It retards calcium scale formation. It is also found in some detergents and cleaning agents. This product is known to be Used in many applications including the purification of antibodies. It is used as a saline laxative to treat constipation or to clean the bowel before a colonoscopy.

Chemical Properties

Disodium phosphate is anhydrous or contains two molecules of water of hydration

Chemical Properties

Sodium hydrogen phosphate,NaH2P04·H20, is hygroscopic, transparent, water-soluble crystals. Used as a purgative, reagent,and buffer.

Chemical Properties

The anhydrous compound is white crystalline powder; hygroscopic; density 1.70 g/cm3; converts to sodium pyrophosphate at 240°C; soluble in water; 874 SODIUM PHOSPHATE, DIBASIC insoluble in alcohol. The dihydrate is a crystalline powder or granular solid; density 2.066 g/cm3 at 15°C; loses water of crystallization at 92.5°C. The heptahydrate is a powdered or granular crystalline solid; density 1.679 g/cm3; loses five molecules of water at 48°C. The dodecahydrate is made up of translucent crystals or granules; density 1.524 g/cm3; readily loses five water molecules on exposure to air at ambient temperature; melts at 35°C when the salt contains all water of crystallization; loses all water at 100°C. All the hydrates are soluble in water and insoluble in alcohol.

Physical properties

The anhydrous compound is white crystalline powder; hygroscopic; density 1.70 g/cm³; converts to sodium pyrophosphate at 240°C; soluble in water;insoluble in alcohol.
The dihydrate is a crystalline powder or granular solid; density 2.066 g/cm³ at 15°C; loses water of crystallization at 92.5°C.
The heptahydrate is a powdered or granular crystalline solid; density 1.679 g/cm³; loses five molecules of water at 48°C.
The dodecahydrate is made up of translucent crystals or granules; density 1.524 g/cm³; readily loses five water molecules on exposure to air at ambient temperature; melts at 35°C when the salt contains all water of crystallization; loses all water at 100°C.
All the hydrates are soluble in water and insoluble in alcohol.

Occurrence

Disodium phosphate is anhydrous or contains two molecules of water of hydration

Uses

Sodium Phosphate Dibasic is used as an in conjunction with trisodium phosphate in foods and water treatment. In foods, it is used to adjust pH. In water treatment, It retards calcium scale formation. It is also found in some detergents and cleaning agents. Sodium Phosphate Dibasic is used as a saline laxative to treat constipation or to clean the bowel before a colonoscopy.

Uses

It is used in pH buffer solutions.

Uses

Sodium Phosphate, Dibasic is used as a laboratory reagent and a buffer in chemical analysis. Other uses are in manufacturing ceramics, detergents, and enamels; as a mordant in dyeing; for fireproofing paper and wood; for weighting and printing silk; in the treatment of boiler water; as a sequestrant in food; as a dietary supplement; in soldering enamels; and in fertilizers. It is used therapeutically as a cathartic.

Definition

ChEBI: Disodium hydrogenphosphate is a sodium phosphate.

Preparation

Dibasic sodium phosphate is prepared by treating phosphoric acid with a slight excess of sodium carbonate. The solution is boiled to expel carbon dioxide. Upon cooling dodecahydrate crystallizes out. Heating dodecahydrate at 100°C forms the anhydrous salt.
H3PO4 + Na2CO3 → Na2HPO4 + CO2 + H2O
Dibasic sodium phosphate also is prepared by reacting dibasic calcium phosphate with sodium carbonate. The product calcium carbonate precipitates leaving dibasic sodium salt in the solution. The solution on cooling yields crystals of hydrated product.
CaHPO4 + Na2CO3 → CaCO3 + Na2HPO4

General Description

Sodium phosphate dibasic in combination with sodium phosphate monobasic is used in the preparation of oral sodium phosphate solution (OSPS), which is a purgative used for bowel cleansing before colonoscopy.

Flammability and Explosibility

Non flammable

Biochem/physiol Actions

Sodium phosphate dibasic is an important component of running buffer of denaturing gel electrophoresis. It induces glomerular calcification as well as other nephrotic syndrome in Sprague-Dawley rats.

Safety Profile

Poison by intravenous route. Moderately toxic by intraperitoneal, subcutaneous, and intramuscular routes. Mildly toxic by ingestion. A skin and eye irritant. When heated to decomposition it emits toxic fumes of POx and Na2O. See also PHOSPHATES.

Purification Methods

Crystallise the salt twice from warm water, by cooling. Dry in air, then in an oven overnight at 130o. It should be dried before use as it is slightly hygroscopic. It forms di-, hepta-and deca-hydrates.

Sodium Phosphate, Dibasic(7558-79-4)Related Product Information

• Trisodium phosphate
• Potassium Phosphate Monobasic
• FERRIC PHOSPHATE
• Sodium Phosphate Monobasic Monohydrate
• Hydrogen
• Calcium phosphate
• Ethylenediaminetetraacetic acid disodium salt
• Ammonium dihydrogen phosphate
• Zinc phosphate
• Creatine phosphate
• Sodium phosphate monobasic
• Sodium Monofluorophosphate
• Ammonium phosphate dibasic
• Potassium Phosphate Dibasic
• Potassium phosphate tribasic
• CERIUM(III) CHLORIDE
• Calcium silicate
• Calcium chloride
• Dibasic Sodium Phosphate
• Sodium Hydrogenphosphate
• Sodium Phosphate Dibasic Anhydrous