Disodium pyrophosphate

Disodium pyrophosphate
	Disodium pyrophosphate
Names
	IUPAC name Disodium dihydrogen diphosphate
	Other names Diphosphoric acid, disodium salt; Disodium dihydrogen pyrophosphate; Disodium diphosphate; Sodium acid pyrophosphate, SAPP
Identifiers
CAS Number	7758-16-9 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL3184949;
ChemSpider	22859 ;
ECHA InfoCard	100.028.941
EC Number	231-835-0;
E number	E450(i) (thickeners, ...)
PubChem CID	24451;
UNII	H5WVD9LZUD ;
CompTox Dashboard (EPA)	DTXSID7044261 ;
	InChI InChI=1S/2Na.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2+1;/p-2 Key: GYQBBRRVRKFJRG-UHFFFAOYSA-L ; InChI=1/2Na.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2+1;/p-2 Key: GYQBBRRVRKFJRG-NUQVWONBAI;
	SMILES [Na+].[Na+].[O-]P(=O)(O)OP([O-])(=O)O;
Properties
Chemical formula	Na2H2P2O7
Molar mass	221.936 g·mol−1
Appearance	White odorless powder
Density	2.31 g/cm3
Melting point	> 600 °C
Solubility in water	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	Disodium phosphate; Pentasodium triphosphate; Sodium hexametaphosphate;
Other cations	Calcium pyrophosphate; Dipotassium pyrophosphate;
Related compounds	Tetrasodium pyrophosphate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Disodium pyrophosphate or sodium acid pyrophosphate (SAPP)^[1] 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

^ "Lallemand Baking Update: Chemical Leaveners Volume 1 / Number 12" (PDF). www.lallemand.com. Lallemand Inc. 1996. Retrieved 6 January 2018.

[Lallemand-1] "Lallemand Baking Update: Chemical Leaveners Volume 1 / Number 12" (PDF). www.lallemand.com. Lallemand Inc. 1996. Retrieved 6 January 2018.

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