Description
Tetrasodium pyrophosphate appears as odorless, white powder or granules. mp: 995°C. Density: 2.53 g/cm³. Solubility in water: 3.16 g/100 mL (cold water); 40.26 g/100 mL boiling water. Used as a wool de-fatting agent, in bleaching operations, as a food additive. The related substance tetrasodium pyrophosphate decahydrate (Na4P2O7*10H₂O) occurs as colorless transparent crystals. Loses its water when heated to 93.8°C.;DryPowder; DryPowder, PelletsLargeCrystals; PelletsLargeCrystals;Colourless or white crystals, or a white crystalline or granular powder. The decahydrate effloresces slightly in dry air;ODOURLESS COLOURLESS OR WHITE CRYSTALS OR POWDER.;Odorless, white powder or granules. [Note: The decahydrate (Na4P2O7 ? 10H₂O) is in the form of colorless, transparent crystals.]
IUPAC Name
tetrasodium; phosphonato phosphate
Molecular Weight
265.90
Molecular Formula
Na4O7P2
Canonical SMILES
[Na+].[Na+].[Na+].[Na+].[O-]P([O-])(=O)OP([O-])([O-])=O
InChI
InChI=1S/4Na.H4O7P2/c;;;;1-8(2,3)7-9(4,5)6/h;;;;(H2,1,2,3)(H2,4,5,6)/q4*+1;/p-4
InChI Key
FQENQNTWSFEDLI-UHFFFAOYSA-J
Boiling Point
Decomposes (NIOSH, 2016);Decomposes
Melting Point
1810 °F (NIOSH, 2016);Mp 993 ° (985 °);988 °C;988 °C;1810°F
Density
2.45 (NIOSH, 2016);2.534;Relative density (water = 1): 2.5;2.45
Solubility
7 % at 77° F (NIOSH, 2016);Soluble in water. Insoluble in ethanol;81.4 mg/mL at 25 °C;IN WATER: 2.61 G/100 ML @ 0 °C; 6.7 G/100 ML @ 25 °C; 42.2 G/100 ML @ 100 °C;(77°F): 7%
Color Form
CRYSTALS;COLORLESS, TRANSPARENT CRYSTALS OR WHITE POWDER;White powder or granules.
Complexity
124
Covalently-Bonded Unit Count
5
Decomposition
When heated to decomp ... emits toxic fumes of /phosphorus oxides/.
EC Number
231-767-1
Exact Mass
265.871
Formal Charge
0
H-Bond Acceptor
7
H-Bond Donor
0
Heavy Atom Count
13
ICSC Number
1140
MDL Number
MFCD00003513
MeSH Entry Terms
anhydrous sodium pyrophosphate;disodium pyrophosphate;sodium diphosphate;sodium pyrophosphate;tetrasodium pyrophosphate;tetrasodium pyrophosphate, 32P2-labeled cpd;tetrasodium pyrophosphate, decahydrate;trisodium pyrophosphate
Monoisotopic Mass
265.871
Odor
Odorless.
Other Experimental
AVAIL ALKALINITY AS NA2O 4.4%, TOTAL ALKALINITY 22.7%;MP: 79.5 °C; DENSITY: 1.82; PH OF 1% SOLN: 10.2 @ 25 °C /DECAHYDRATE/;COLORLESS, MONOCLINIC CRYSTALS; INSOL IN AMMONIA /DECAHYDRATE/;INSOL IN ALCOHOL /DECAHYDRATE/;SOLUBILITY IN WATER: 3.16 G/100 ML @ 0 °C; 6.23 G/100 ML @ 20 °C; 8.14 G/100 ML @ 25 °C; 21.83 G/100 ML @ 60 °C; 30.04 G/100 ML @ 80 °C /DECAHYDRATE/;INDEX OF REFRACTION: 1.450, 1.453, 1.460 /DECAHYDRATE/;SLIGHT EFFLORESCENCE IN DRY AIR /DECAHYDRATE/;HYDROLYZES TO ORTHOPHOSPHATE IN AQ SOLN, BUT RATE OF HYDROLYSIS IS MUCH SLOWER THAN FOR MORE ACID PYROPHOSPHATE; NO NOTICEABLE HYDROLYSIS WITHIN 60 HR AT 70 °C
Physical State
Colorless to White Powder
Refractive Index
INDEX OF REFRACTION: 1.425
Rotatable Bond Count
0
RTECS Number
UX7350000
UNII
O352864B8Z
Vapor Pressure
0 mm Hg (approx) (NIOSH, 2016);0 mmHg (approx)
