SODIUM HYDROSULFITE

PRODUCT IDENTIFICATION

CAS NO. 7775-14-6

SODIUM HYDROSULFITE

EINECS NO. 231-890-0
FORMULA Na2O4S2 (Sodium Dithionite)
MOL WT. 174.10

HS CODE

2831.10.5000

TOXICITY

Oral Rat LD 50: 5 g/kg.

SYNONYMS Sodium dithionite; Reductone; Vatrolite;
Sodium sulfoxylate; Dithionous acid,disodium salt; Sodium dithionite hydrate;
SMILES [O-]S(=O)S(=O)[O-].[Na+].[Na+]

CLASSIFICATION

Bleach, Dithionite

EXTRA NOTES

 

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE White crystalline powder with weak sulforous odor
MELTING POINT 52 C
BOILING POINT Decomposes
SPECIFIC GRAVITY 2.19 - 2.20
SOLUBILITY IN WATER 250 g/l (insoluble in alcohol)
pH Acidic in solution
VAPOR DENSITY  

AUTOIGNITION

 

NFPA RATINGS

Health: 2; Flammability: 3; Reactivity: 1

REFRACTIVE INDEX

 

FLASH POINT 90 C
STABILITY Stable under ordinary conditions (Decomposes in hot water and acid)

EXTERNAL LINKS & GENERAL DESCRIPTION

USA.gov - Sodium Hydrosulfite

Wikipedia Linking - Sodium dithionite

Google Scholar Search - Sodium Hydrosulfite

U.S. National Library of Medicine - Sodium Hydrosulfite

PubChem Compound Summary - Sodium Hydrosulfite

IPCS INCHEM -  Sodium Hydrosulfite

KEGG (Kyoto Encyclopedia of Genes and Genomes) -  Sodium Hydrosulfite

ChEBI (http://www.ebi.ac.uk/chebi/) -  Sodium Hydrosulfite

NCBI (http://www.ncbi.nlm.nih.gov/) -  Sodium Hydrosulfite

Material Safety Data Sheet - Sodium Hydrosulfite

Hazardous Substances Data Bank - Sodium Hydrosulfite

EPA - Substance Registry Services - Sodium Hydrosulfite

Local:
Sodium Hydrosulfite is a white powder. Commercial sodium hydrosulfite contains 85% - 90% sodium dithionite w/w. It is readily soluble in water and shows powerful reducing action in aqueous solutions. Sodium hydrosulfite is used as a reducing agent in dying application. It undergoes reduction reaction with water-insoluble vat dye and sulfur dye to form water-soluble alkali metal salt of the dye (leuco form ) so that they have affinity for the textile fiber. The reductive decomposition of the excessive dye by sodium hydrosulfite improve the colour fastness. Sodium hydrosulfite's reduction reaction removes residual oxide and wrong pigments. Sodium hydrosulfite is a reductive bleaching agent. It reduces carbonyl and alcohol groups, which function as colorants of the substances. It is used in bleaching mechanical paper pulp, cotton, wool and kaolin clay. Additional applications include water treatment, leather processing, food processing, gas purification, cleaning, printing and stripping. In addition to a reducing agent function, sodium hydrosulfite functions as a sulfonating agent and sodium ion source in a variety of chemical reactions.

SULFURIC SALTS: Sulfate (also spelled sulphate in Europe) is any chemical compound containing the SO42- ion related to sulfuric acid (H2SO4). Sulfates are salts or esters of sulfuric acid, formed by replacing one or both of the hydrogens with a metal or a radical as in sodium sulfate, Na2SO4. Sulfates in which both hydrogens are replaced are called normal sulfates. Bisulfate is a compound that has the HSO4- radical. Bisulfate (called also hydrogen sulfate or acid sulfate) is a compound formed by replacing only one hydrogen in sulfuric acid. Sulfite (also sulphite) is a compound that contain the sulfite ion SO32-. Sulfites are salts or esters of sulfurous acid (H2SO3), formed by replacing one or both of the hydrogens with a metal or a radical as in sodium sulfite, Na2SO3. Sulfites in which both hydrogens are replaced are called normal sulfites. Bisulfite is a compound that has the HSO3- radical. Bisulfate (called also hydrogen sulfite or acid sulfite) is a compound formed by replacing only one hydrogen in sulfurous acid. The term of 'meta' or 'pyro' is the chemical prefix for oxo acid formed through the loss of one water molecule (dehydration) from two molecules of ortho acid by heating. Pyrosulfuric acid is an example ( 2H2SO4 - H2O = H2S2O7). Ortho acid is the compound fully hydrated acid or its salts. Orthophosphoric acid is an example (H3PO4 = P2O5.3H2O), in contrast to the less hydrated form, pyrophosphoric acid (HPO3 = P2O5.H2O). Na2O5S2 is called sodium metabisulfite (2·HNaO3S - H2O). Sulfide is a compound having one or more sulfur atoms in which the sulfur is connected directly to a carbon, metal, or other nonoxygen atom; for example sodium sulfide, Na2S. Sulfide ion is S2- with oxidation number -2. Bisulfide ion is an anion formed by two sulfur atoms having an overall -2 charge, (S2)2-. Sulfamate is a salt of sulfamic acid (HSO3NH2). Calcium sulfamate Ca(SO3NH2)2 is an example.

SALES SPECIFICATION

APPEARANCE

White to Gray-White crystalline powder
Na2O4S2

85% or 88% or 90% min

INSOLUBLES IN WATER

0.1% max

Na2S2O3

1.2% max

Na2S2O5

5-7%

NaHSO3

0.5% max

Na2CO3

0.6-2%

HCOONa

0.5% max

Pb

0.0001% max

Fe

0.005% max
TRANSPORTATION
PACKING  
HAZARD CLASS

4.2 (Packing Group:II)

UN NO. 1384
SAFETY INFORMATION

HAZARD OVERVIEW

GHS (Globally Harmonised System) Classification: Self-heating substances. Acute toxicity (Oral). Acute aquatic toxicity. Hazard statements: Self-heating: may catch fire. Harmful if swallowed. Toxic to aquatic life. Contact with acids liberates toxic gas

GHS

 

SIGNAL WORD

Danger

PICTOGRAMS

PICTOGRAM_GHS07_exclamation.jpgPICTOGRAM_GHS02_flame.jpg

HAZARD STATEMENTS

H251-H302-H402

P STATEMENTS

P235 + P410

EC DIRECTIVES

 

HAZARD CODES

CODE_Xn_Xi_harmful_Irritant.gif

RISK PHRASES

7-22-31

SAFETY PHRASES

7/8-26-28-43

PRICE INFORMATION

 

 

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