Sodium bisulfite

chemical compound


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
Ball-and-stick model of a bisulfite anion (left) and a sodium cation (right)
Names
IUPAC name
Sodium hydrogen sulfite
Other names
E222, sodium bisulphite
Identifiers
  • 7631-90-5 checkY
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.028.680
E number E222 (preservatives)
RTECS number
  • VZ2000000
  • [Na+].[O-]S(=O)O
Properties
NaHSO3
Molar mass 104.061 g/mol
Appearance White solid
Odor Slight sulfurous odor
Density 1.48 g/cm3
Melting point 150 °C (302 °F; 423 K)
Boiling point 315 °C (599 °F; 588 K)
42 g/100mL
1.526
Hazards
EU classification Harmful (Xn)
NFPA 704

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 {{{value}}}
Other cations {{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
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References

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