Potassium Metabisulfite

Sodium pyrosulfite, also known as reduced pyrosulfite, disulfur pentoxide sodium, or heavy sulfur oxide, is an inorganic salt compound with the chemical formula Na2S2O5, and its molecular weight is 190.10. It appears as white or slightly yellow crystalline powder or small crystals, with a strong sulfur dioxide odor. Its density is 1.4 g/cm3, and it is soluble in water and glycerol, slightly soluble in alcohols. The solubility in water increases with the increase in temperature [6]. Sodium pyrosulfite is a strong reducing agent and can react with elemental iodine and methanol to form sulfur dioxide, sodium iodide, and monomethyl sulfate [10]. When sodium pyrosulfite dissolves in water, it forms stable sodium bisulfite, and the aqueous solution is acidic. It releases sulfur dioxide when reacting with sulfuric acid, and forms sodium sulfite when reacting with caustic soda or soda ash [6]. Sodium pyrosulfite is prone to oxidation in the air and turns into sodium sulfate when exposed to the air. It decomposes when heated to 150°C.

Products Description

Alternative names: Sodium dithionite, Sodium heavy sulfite
Chemical formula: Na2S2O5
Molecular weight: 190.107
CAS number: 7681-57-4
EINECS number: 231-673-0
Melting point: 150 ℃(decomposes)
Water solubility: Soluble
Density: 1.48 g/cm³
Appearance: White crystalline powder
Applications: Antioxidant

Melting point	150℃
Density	1.48g/cm3
PSA	124.92000

LogP	0.27220
Appearance	White crystalline powder, with the odor of sulfur dioxide
Solubility	It dissolves in water and the resulting aqueous solution is acidic. It is soluble in glycerol and slightly soluble in ethanol.

Properties and Stability:
1. It decomposes easily when exposed to moisture and oxidizes in the air to form sodium sulfate. It is irritating.
2. When in contact with strong acids, it releases sulfur dioxide and forms corresponding salts. It decomposes at 150°C. It is a white powder with a strong SO2 odor. It loses SO2 in the air and absorbs O2 to transform into Na2SO4. It is soluble in water, and the aqueous solution is acidic. When the solution is heated above 65°C, it decomposes into Na2SO3 and SO2.

Products Application

It is used for the production of sodium peroxide, sulfadimidine, paracetamol, caprolactam, etc.; it is used for the purification of chloroform, benzophenone and benzaldehyde. In the photography industry, it is used as a component of the fixing agent; in the perfume industry, it is used to produce vanillin; it is used as a preservative in the brewing industry; as a rubber setting agent and a chlorine remover after cotton fabric bleaching; as an organic intermediate; for dyeing and tanning; as a reducing agent; used in the electroplating industry, oil fields' wastewater treatment and as a mineral separation agent in mines; in food processing, it is used as a preservative, bleaching agent and leavening agent.

Products Qualification

1-25

2-25-tic

4-tic

7-2-tic

11-tic

Hot Tags: potassium metabisulfite, China potassium metabisulfite manufacturers, suppliers