Physical and Chemical properties of Sodium Metabisulfite
Physical and Chemical properties of Sodium Metabisulfite
Product Sodium Metabisulfite
Synonyms Sodium Pyrosulfite, SMBS
Appearance White crystalline powder
CAS No 7681-57-4
EINECS No 231-673-0
Molecular Weight 190.107
Melting Point 150℃ (Decomposed)
Density 1.48 g/cm³
Accurate Mass 189.898254
Water Solubility 540g/L (20 ℃)
Purity 97% Min
Storage Conditions Sodium Metabisulfite should be stored in a cool and dry warehouse. The packaging should be sealed to prevent air oxidation.

Pay attention to moisture prevention. During transportation, it should be protected from rain and scorching sun. Sodium Metabisulfite is strictly prohibited to store and transport together with acids, oxidants, and toxic and harmful substances.

When a fire occurs, water and various fire extinguishers can be used to extinguish it.

Stability Sodium Metabisulfite is easy to decompose when exposed to moisture and oxidize into sodium sulfate when exposed to air. Irritating.

Contact with strong acids releases sulfur dioxide and generates corresponding salts. Heat to 150 ℃ for decomposition. A white powder with a strong SO2 odor that loses SO2 in the air and absorbs O2, transforming into Na2SO4. Sodium Metabisulfite is easily soluble in water and the aqueous solution is acidic. When the solution is heated above 65 ℃, it decomposes into Na2SO3 and SO2.