Sodium bisulfite

Sodium bisulfite, also known as sodium hydrogen sulfate, is a chemical compound. Its chemical formula is NaHSO3. It is made of sodium and bisulfite ions. It is a white solid with an odor of sulfur dioxide. It can be made by reacting smaller amounts of sodium dioxide and sodium hydroxide or sodium bicarbonate. If too much sodium hydroxide is used, sodium disulfite is made instead.

Sodium bisulfite
Sodium bisulfite.png
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IUPAC name Sodium hydrogen sulfite
Other names E222, sodium bisulphite
Identifiers
CAS number 7631-90-5
PubChem 23665763
ChEBI CHEBI:26709
RTECS number VZ2000000
SMILES [Na+].[O-]S(=O)O
Properties
Molecular formula NaHSO3
Molar mass 104.061 g/mol
Appearance White solid
Odor Slight sulfurous odor
Density 1.48 g/cm3
Melting point

150 °C, 423 K, 302 °F

Boiling point
Solubility in water 42 g/100mL
Refractive index (nD) 1.526
Hazards
EU classification Harmful (Xn)
NFPA 704

NFPA 704.svg

0
2
1
 
R-phrases R22 R31
S-phrases (S2), S25, S46
Flash point Non-flammable
U.S. Permissible
exposure limit (PEL)
none[1]
Related compounds
Other anions Sodium sulfite
Sodium metabisulfite
Other cations Potassium bisulfite
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Related pages

References

  1. NIOSH Pocket Guide to Chemical Hazards. "#0561". National Institute for Occupational Safety and Health (NIOSH).