Sodium pyrosulfate

Sodium pyrosulfate

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Names
IUPAC name Disodium disulfate
Other names Sodium pyrosulphate; Disulfuric acid disodium salt.
Identifiers
CAS Number	13870-29-6 Y
ChEMBL	ChEMBL111016 N
Jmol 3D model	Interactive image
SMILES [Na+].[Na+].[O-]S(=O)(=O)OS(=O)(=O)[O-]
Properties
Chemical formula	Na2S2O7
Molar mass	222.12 g/mol
Appearance	Translucent white crystals
Density	2.658 g/cm3
Melting point	400.9 °C (753.6 °F; 674.0 K)
Boiling point	decomposes at 460 °C (860 °F; 733 K)
Solubility in water	Soluble
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Sodium pyrosulfate, or Disodium disulfate, is an inorganic compound with the chemical formula is Na₂S₂O₇.

Preparation

Sodium pyrosulfate is obtained by the dehydration of sodium bisulfate:

2 NaHSO₄ → Na₂S₂O₇ + H₂O

Temperatures above 460°C further decompose the compound, producing sodium sulfate and sulfur trioxide:

Na₂S₂O₇ → Na₂SO₄ + SO₃

Applications

Sodium pyrosulfate is used in analytical chemistry; samples are fused with sodium pyrosulfate to ensure complete dissolution prior to a quantitative analysis.

See also

• Pyrosulfate
• Potassium bisulfate
• Potassium pyrosulfate