Sodium Phosphates Injection, USP, ... is indicated as a source of phosphorus, for addition to large volume intravenous fluids, to prevent or correct hypophosphatemia in patients with restricted or no oral intake.Disodium hydrogen phosphate Cas No 7558-79-4 It is also useful as an additive for preparing specific parenteral fluid formulas when the needs of the patient cannot be met by standard electrolyte or nutrient solutions. Disodium hydrogen phosphate Cas No 7558-79-4 Although sodium and/or potassium phosphates have been used in the treatment of hypercalcemia, USP medical advisory panels do not recommend this use since these medications have been replaced by safer and more effective agents. Disodium hydrogen phosphate Cas No 7558-79-4 Disodium phosphate (DSP), also known as sodium hydrogen phosphate or sodium phosphate dibasic, is an inorganic compound with the chemical formula Na2HP04.
Disodium hydrogen phosphate Cas No 7558-79-4
It is white crystalline and odorless. It is one of several types of sodium phosphate. Di sodium phosphate salt exists in 2, 7, 8 and 12 hydrated forms as well as in anhydrite form. They are completely water-soluble white powders; The salt form in the anhydrite structure is hygroscopic.

Disodium hydrogen phosphate Cas No 7558-79-4

The pH of the disodium hydrogen phosphate aqueous solution is between 8.0 and 11.0, which indicates that it is moderately basic:

HPO42− + H2O ⇌ H2PO4− + OH−

As a result of the neutralization reaction of phosphoric acid with sodium hydroxide:

Disodium hydrogen phosphate Cas No 7558-79-4

H3PO4 + 2 NaOH → HNa2PO4 + 2 H2O

It is produced industrially by treating dicalcium phosphate with sodium bisulfate, in which calcium sulfate is precipitated, in a two-step process:

Disodium hydrogen phosphate Cas No 7558-79-4

CaHPO4 + NaHSO4 → NaH2PO4 + CaSO4

In the second step, the resulting monosodium phosphate solution is partially neutralized:

NaH2PO4 + NaOH → HNa2PO4 + H2O

It is used in the food industry to soften trisodium phosphate and water. It is used to adjust the pH in foods. Its use prevents coagulation in condensed milk. It is also used as an anti-caking additive in powder products. It is used in desserts and puddings. It is especially used to reduce cooking time.

It delays the formation of calcium when used in water treatment. It is also found in many detergents and hygiene products.
Disodium hydrogen phosphate Cas No 7558-79-4

Heating solid disodium phosphate yields the useful compound tetrasodium pyrophosphate. This reaction:

Disodium hydrogen phosphate Cas No 7558-79-4
2 HNa2PO4 → Na4P2O7 + H2O
Monobasic and dibasic types of sodium phosphate are used as laxatives to treat constipation or to clear the bowels before colonoscopy. Disodium hydrogen phosphate Cas No 7558-79-4