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CAS NUMBER: 7757-83-7
EC NUMBER: 231-821-4
MOLECULAR FORMULA: Na2SO3
MOLECULAR WEIGHT: 126.04
Sodium sulfite is the inorganic compound with the chemical formula Na2SO3.
A white, water-soluble solid, Sodium sulfite is used commercially as an antioxidant and preservative.
A heptahydrate is also known but Sodium sulfite is less useful because of its greater susceptibility toward oxidation by air.
Sodium sulfite can be prepared by treating a solution of sodium hydroxide with sulfur dioxide.
When conducted in warm water, Na2SO3 initially precipitates as a white solid.
With more Sodium sulfite, the solid dissolves to give the disulfite, which crystallizes upon cooling.
Sodium sulfite is primarily used in the pulp and paper industry.
Sodium sulfite has been also applied in the thermomechanical conversion of wood to fibres (defibration) for producing medium density fibreboards (MDF).
As an oxygen scavenger agent, Sodium sulfite is used to treat water being fed to steam boilers to avoid corrosion problems, in the photographic industry, it protects developer solutions from oxidation and (as hypo clear solution) to wash fixer (sodium thiosulfate) from film and photo-paper emulsions.
As a reducing agent Sodium sulfite is used in the textile industry as a bleaching, desulfurizing, and dechlorinating agent (e.g. in swimming pools).
Sodium sulfites reducing properties are exploited in its use as a preservative to prevent dried fruit from discoloring, and for preserving meats.
Sodium sulfite is used as a reagent in sulfonation and sulfomethylation agent.
Sodium sulfite is used in the production of sodium thiosulfate.
Sodium sulfite is primarily used as a mild reducing agent.
Sodium sulfite crystals effloresce in warm dry air.
Sodium sulfite crystals also oxidize in air to form sodium sulfate.
Sodium sulfite form is more resistant to oxidation by air.
Sodium sulfite is mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions.
Sodium Sulfite is a white crystal or powder with reducing property. Sodium sulfite exhibits bleaching, de-sulfurizing, and dechlorinating activities.
Sodium sulfite was used by food industry to help maintain the fresh appearance of food products.
Sodium sulfite is also a component in many drugs, which helps maintain their potency and stability.
Sodium sulfite is a white odorless powder. Density 2.633 g / cm3.
Sinks in water and dissolves slowly.
Also transported as a heptahydrate Na2SO3.7H2O.
Sodium sulfite is an inorganic sodium salt having sulfite as the counterion.
Sodium sulfite has a role as a food preservative and a reducing agent.
Sodium sulfite is an inorganic sodium salt and a sulfite salt.
Sodium sulfite contains a sulfite.
Sodium sulfite is an odorless, solid white powder with a salty sulfurous taste that is soluble in water.
Sodium sulfite is primarily used as a food preservative (e.g., to prevent dried fruit from discoloring) and as an antioxidant.
In the past, sodium sulfite was used to make pulp in the paper industry, but its use now accounts for less than 10% of the total pulp production, and the number of sulfite mills continues to decrease.
Sodium sulfite is also used water treatment and photography.
There is very little information on the environmental fate and effects of sodium sulfite and it is anticipated that, if released to water or soil, the effects would be negligible.
Because Sodium sulfite is used in small amounts as a food preservative, a very small percentage of the population is ‘sensitive’ to the chemical and may have an allergic reaction; some asthmatics may have a severe reaction following exposure.
There are no environmental standards or regulations for sodium sulfite as it is ‘generally recognized as safe’ when used as a chemical preservative.
Sodium sulfite is not an ‘environmental’ pollutant per se, but its wide use as a food additive may lead to widespread exposure of the general population to trace amounts through ingestion.
This may pose a problem for a small percentage of people who are hypersensitive to this chemical.
Exposure to elevated concentrations (i.e., those that might cause abject toxicity) of this compound would only be expected to occur in the workplace, primarily involving sources of production or bulk use as mentioned previously.
Because Sodium sulfite is packaged as a powder, exposure would be expected to occur from airborne dust.
Potential exposure routes would thus include skin, inhalation, and possibly involvement of the eye, nose, and throat.
Sodium sulfite is a white, water-soluble, crystalline solid with a sulfurous, salty taste.
Sodium sulfite decomposes when heated.
Sodium sulfite is generally available f in powder, crystalline, and tablet forms.
Sodium sulfite is yet another dechlorinating agent widely used by utilities.
Sodium sulfite is generally available in powder form.
In addition, some companies manufacture in tablet form. Sodium sulfite is slightly alkaline in nature.
Sodium sulfite is a reducing agent and is reported to scavenge more oxygen than sodium thiosulfate.
Food industry used sodium sulfite to assist the preservation of the new appearance of food products.
In many drugs, Sodium sulfite is also an element that helps to preserve their potency and stability.
Sodium sulfite has been approved by the FDA as a fresh low regulatory priority animal drug.
Sodium sulfite is an inorganic salt with the chemical formula Na2SO3.
Sodium sulfite is an ionic compound containing two sodium cations (Na+) and one sulfite anion (SO32-).
A saturated solution of sodium sulfite in water is mildly basic with an approximate pH value of 9.
Such a solution can undergo crystallization to yield heptahydrate crystals of Na2SO3.
In Sodium sulfites anhydrous form, sodium sulfite is a white solid.
The primary difference between anhydrous Sodium sulfite and its heptahydrate is the relative stability of the anhydrous form towards oxidation.
Sodium sulfite is slowly oxidized by atmospheric oxygen, giving rise to the corresponding sulfate.
Each sodium ion holds a charge of +1. On the other hand, the -2 charge on the sulfite ion is delocalized due to resonance, resulting in a partial charge of -⅔ on each oxygen atom.
The overall charge on a Na2SO3 molecule is zero.
The depletion of the NaOH reactant can be detected via the addition of a few drops of concentrated H2SO4, resulting in the liberation of SO2 gas.
Sodium sulfite is used as a sulfonation and sulfomethylation agent in the chemical manufacturing industry.
Sodium sulfite is also used for the sodium thiosulfate production.
Sodium sulfite has several other important applications, including froth ores flotation, oil recovery, food preservatives, and colouring.
Sodium sulfite is a salt made from the neutralization reaction between a strong base (sodium hydroxide) and a weak acid (sulphurous acid).
Sodium sulfites aqueous solution is, therefore, distinctly basic in nature, with a pH value slightly greater than 7.
Sodium sulfite is an ionic compound which crystallizes in a hexagonal crystal lattice in its anhydrous form.
However, Sodium sulfite crystallizes in a monoclinic lattice when it is in its heptahydrate form.
Sodium sulfite can be prepared by the treatment with sulfur dioxide of a sodium hydroxide solution.
Sodium sulfite initially precipitates as a yellow solid when performed in warm water.
Sodium sulfite dissolves with more SO2 to give the disulfite, which crystallizes as it cools down.
Sodium sulfites have been used as food additives primarily to improve taste and maintain freshness.
But these sulfur-based compounds also occur naturally in foods, such as fermented beverages and wines.
For a number of drugs, they are often used as a preservative to help improve shelf life.
Sodium sulfite also finds use in the froth flotation process of purifying ores, extraction of petroleum, and the production of some dyes.
Sodium sulfite, the aqueous ion of sulfur dioxide, has been reported to contain pro-inflammatory properties in vitro and induce potent chemotactic factor IL-8 production.
Mechanistic studies suggest that this compound could possibly act through signal transduction pathways NF-κ B, ERK, and p-38-dependent pathways.
Sodium sulfite has also been shown to inhibit Candida albicans growth in RPMI1640 medium.
Additional experiments note that this agent can induce cellular activation, resulting in degranulation in mast cells through a non-IgE-depent pathway.
Sodium Sulfite – Catalyzed is an inorganic compound with the chemical formula Na₂SO₃.
Sodium sulfite is also known as Salt Cake.
Sodium Sulfite is primarily used as an oxygen scavenger in water-based oil drilling fluid systems.
Sodium sulfite has a white/ pale yellow appearance and is odorless.
Sodium sulfite is soluble in water and is catalyzed using a cobaltous compound.
Sodium Sulfite increases the lifespan of organic polymers.
Sodium sulfite achieves this by eliminating the conditions that encourage their thermal degradation.
Sodium sulfite saves companies money as it reduces the amount of use of these polymers.
As an oxygen scavenger, Sodium Sulfite is added continually until the residual sulfite (SO3) concentration in the mud filtrate reaches or exceeds the levels required.
After that, this level can be sustained with daily treatments.
The amounts required will depend on the severity of the dissolved oxygen content in the drilling mud.
Sodium sulfite is used as a drilling mud additive to assist in borehole stability while drilling through evaporated beds and stringers such as anhydrite.
Sodium sulfite reduces the anhydrite solubility, thus decreasing the hole enlargement through evaporation.
Sodium sulfite can be used in some brine muds and completion fluids to reduce corrosion resulting from dissolved oxygen.
During the enhanced oil recovery process (EOR), Sodium Sulfite can increase specific polymers’ stability at high temperatures.
Sodium sulfite exhibits bleaching, de-sulfurizing, and dechlorinating activities.
Sodium Sulfite can quickly breakdown.
Sodium sulfite is usually added at a concentration of one to two sacks to a barrel of water.
After mixing, the mixture should be covered with an appropriate cover to reduce the amount of oxygen from the air that the mixture might absorb.
Sodium sulfite should be added to the drilling fluid system with an injection pump.
Sodium sulfite is defined as a white, crystalline, water-soluble solid with a sulfurous and salty taste.
When heated, Sodium sulfite decomposes, and Sodium sulfite is generally available in crystalline, tablet and powder forms.
The chemical formula of sodium sulphite is given as Na2SO3.
Sodium sulfite is yet another dechlorinating agent which can be widely used by utilities.
Generally, Sodium sulfite is available in powder form.
In addition, a few companies manufacture this compound in tablet form.
Sodium sulfite compound is a reducing agent, and it is reported to scavenge more oxygen compared to sodium thiosulfate.
Sodium sulfite is defined as an inorganic salt having the chemical formula as Na2SO3.
Sodium sulfite is an ionic compound that contains two sodium cations (Na+) and single sulfite anion (SO32-).
A saturated solution of sodium sulfite present in the water is mildly basic with a nearby pH value of 9.
Such a solution undergoes crystallization to yield heptahydrate crystals of Na2SO3.
The food industry uses sodium sulfite to assist the new appearance of food products preservation.
In several drugs, Sodium sulfite is also a compound that helps in the preservation of their stability and potency.
Sodium sulfite compound has been approved as a fresh low regulatory priority.
Sodium sulfite, in Sodium sulfites anhydrous form, as represented above, is a white solid.
The major difference between anhydrous Na2SO3 and its heptahydrate is given as the relative stability of the anhydrous form towards the oxidation process.
Sodium sulfite is slowly oxidized by the atmospheric oxygen by giving rise to the corresponding sulfate.
As a soluble sodium salt of sulfurous acid, Sodium sulfite (Na2SO3) shows blenching, de-sulfurizing and dechlorinating properties which is widely applied in various fields.
Sodium sulfite is primarily used in the pulp and papermaking industry due to its blenching activity.
Sodium sulfite can serve as a good additive to help preserve the fresh appearance of good products.
Besides, sodium sulfite is a component in many pharmaceuticals, which is effective to maintain the potency and stability of drugs.
Sodium sulfite can also be applied for water treatment as an oxygen scavenger agent and applied in flue gas desulfurization and preservation of photo developer solutions, etc.
Sodium sulfite occurs as an odorless white powder or hexagonal prisms.
Note that the commercially available sodium sulfite is often presented as a white to tan- or pink-colored powder that would not conform to the pharmacopeial specification.
Sodium sulfite is a white,water-soluble, crystalline solid with a sulfurous, salty taste.
Sodium sulfite decomposes when heated. Sodium sulfite is used as a source of sulfite,as a chemical intermediate and food preservative, in medicine and paper manufacturing, in photographic developing, and as a bleaching agent in the textile industry.
Most boiler operators use sodium sulfite for chemicals cavenging of oxygen in the feedwater.
Because Sodium sulfite decomposes into acidic gases at the high temperatures that accompany high pressures, sodium sulfite should not be used for this purpose at pressures above 122atm (12.4MPa,or 1.8 ksi).
These white crystals were prepared by passing sulfurous gas over moist sodium carbonate.
Sodium sulfite is soluble in water but less so in alcohol.
Sodium sulfite was used as a preservative for alkaline developers and as a hypo clearing agent in photographic printing.
Sodium sulfite is prepared by reacting sulfur dioxide gas with sodium hydroxide solution.
The solid material is obtained by evaporation of water.
Further neutralization with sodium hydroxide while keeping the temperature above 33.6°C leads to crystallization of the anhydrous sodium sulfite.
Sodium sulfite, A white solid,Na2SO3, existing in an anhydrousform and as a heptahydrate(r.d. 1.59).
Sodium sulfite is solublein water and because Sodium sulfite is readily oxidizedit is widely used as a convenientreducing agent.
Sodium sulfite is preparedby reacting sulphur dioxide with eithersodium carbonate or sodium hydroxide.
Dilute mineral acids reversethis process and release sulphur dioxide.
Sodium sulphite is used as ableaching agent in textiles and inpaper manufacture.
Sodium sulfites use as an antioxidantin some canned foodstuffsgives rise to a slightly sulphuroussmell immediately on opening, butits use is prohibited in meats or foodsthat contain vitamin B1.
Sodium sulphitesolutions are occasionally usedas biological preservatives.
Sodium sulfite is used as an antioxidant in applications similar to those for sodium metabisulfite.
Sodium sulfite is also an effective antimicrobial preservative, particularly against fungi at low pH (0.1% w/v of sodium sulfite is used).
Sodium sulfite is used in cosmetics, food products, and pharmaceutical applications such as parenteral formulations, inhalations, oral formulations, and topical preparations.
USES:
Sodium sulfite is often used to prevent the discolouration of dried fruits since it can act as a preservative.
Sodium sulfite is also used in swimming pools to decrease the chlorine levels in the water.
In boiler systems, Sodium sulfite acts as an oxygen scavenger to protect the system from pitting corrosion.
Therefore, the water fed to boilers is often treated with sodium sulfite.
The textile industry makes extensive use of Sodium sulfite for bleaching, dechlorinating and desulfurizing purposes.
Sodium sulfite is also used in the process of purifying trinitrotoluene (TNT) in order to make it fit for military use.
Sodium sulfite is also an important component in the preparation of sodium thiosulfate.
-In chemical industry in the production of dyes, detergents, organic intermediates, etc.
-As oxygen scavenger in steam boiler treatment and in sea water desalting treatment via multi-flash.
-In tanneries as auxiliary in tanning process.
-In textile as dechlorinating agent and bleaching adjuvant.
-In pulp and paper industry in the production of chemimechanical, chemithermomechanical and sulphite pulp.
-In wood panels production, in order to reduce formaldehyde emissions.
-In extracting industry as oxygen scavenger in drilling water.
-In plating, as reducer to prevent cianate yielding.
APPLICATION:
-Dechlorination in municipal wastewater, pulp & paper, power, and textile water treatment plants
-Boiler water treatment
-Oxygen scavenger
-Flue gas desulfurization
-Chemical manufacturing in the sulfonation process
PHYSICAL PROPERTIES:
The molar mass of Sodium sulfite is 126.043 grams per mole.
Sodium sulfite exists as a white, odourless solid which has a density of 2.633 grams per cubic centimetre.
The heptahydrate form has a relatively lower density of 1.561 g/cm3.
When heated to 306.5K (33.4oC), the heptahydrate undergoes dehydration.
The anhydrous form melts at a temperature of 500o
Sodium sulfite does not have a specific boiling point since Sodium sulfite tends to decompose at high temperatures.
Sodium sulfite is moderately soluble in water, its solubility corresponds to 27g/100mL.
The crystal structure of anhydrous Sodium sulfite is hexagonal whereas the heptahydrate crystals have a monoclinic structure.
CHEMICAL PROPERTIES:
Upon contact with strong or weak acids, Sodium sulfite undergoes decomposition, liberating gaseous sulfur dioxide.
Sodium sulfite reacts with aldehydes to yield a bisulfite adduct.
However, sulfonic acids are produced from Sodium sulfites reaction with ketones.
Solutions of sodium sulfite are oxidized by atmospheric oxygen, yielding sodium sulfate.
Sodium sulfite is insoluble in ammonia and chlorine.
STRUCTURE:
According to X-ray crystallography sodium sulfite heptahydrate features pyramidal SO32- centers.
The S-O distances are 1.50 and the O-S-O angles are near 106º.
CHEMICAL IDENTIFIERS:
-Linear Formula: Na2SO3
-MDL Number: MFCD00003503
-EC No.: 231-821-4
-Pubchem CID: 24437
-IUPAC Name: disodium; sulfite
-SMILES: [O-]S(=O)[O-].[Na+].[Na+]
-InchI Identifier: InChI=1S/2Na.H2O3S/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2
-InchI Key: GEHJYWRUCIMESM-UHFFFAOYSA-L
PROPERTIES:
-Quality Level: 300
-agency: reag. Ph. Eur.
-assay: 97.0-100.5% (iodometric)
-form: powder
-potency: 2610 mg/kg LD50, oral (Rat)
-pH: 8.8-10 (20 °C, 50 g/L in H2O)
-mp: >500 °C (decomposition)
-density: 2.63 g/cm3 at 20 °C
-bulk density: 1480 kg/m3
PHYSICAL AND CHEMICAL PROPERTIES:
-Density: 2.630 g/cm3
-Melting Point: >500 °C (decomposition)
-pH value: 9.0 - 10.5 (126 g/l, H₂O, 25 °C)
-Bulk density: 1480 kg/m3
-Solubility: 220 g/l
TECHNICAL INFORMATION:
-Physical State: Solid
-Solubility: Soluble in water (230 g/l at 20° C), and glycerol.
-Insoluble in alcohol, liquid chlorine, and liquid ammonia.
-Storage: Store at room temperature
-Melting Point: >500° C
-Density: 2.63 g/cm3 at 20° C
-Refractive Index: n20D 1.57
-pK Values: pKa: 1.53
STORAGE:
Store at +2°C to +30°C.
Store long-term in a cool, dry place.
Sodium sulfite should be stored in a well-closed container in a cool, dry, place.
In solution, sodium sulfite is slowly oxidized to sulfate by dissolved oxygen; strong acids lead to formation of sulfurous acid/ sulfur dioxide.
On heating, sodium sulfite decomposes liberating sulfur oxides.
SYNONYM:
7757-83-7
Sodium sulphite
Sodium sulfite anhydrous
Disodium sulfite
Sulfurous acid, disodium salt
Natrium sulfurosum
Natriumsulfid
Natriumsulfit
Anhydrous sodium sulfite
Sodium sulfite (Na2SO3)
UNII-VTK01UQK3G
Sulfurous acid, sodium salt (1:2)
Sodium sulfite
Na2SO3
MFCD00003503
VTK01UQK3G
Sulftech
CHEBI:86477
Sodium sulfite
sodiumsulfite
Natrii sulphis
Natriumsulfid
Natriumsulfit
S-WAT
Exsiccated sodium sulfite
Sodium sulfite, exsiccated
