Sodium sulfite (Sodium chemical formula: Na2SO3) is an inorganic compound. It is a white granular powder at room temperature, stable on drying and sensitive to moisture. Soluble in water and glycerin, insoluble in ethanol, aqueous solution is alkaline, its aqueous solution is alkaline to litmus paper and phenolphthalein, and produces toxic sulfur dioxide gas with acid. The pH of 1% aqueous solution is 8.3~9.4, strong reduction Sex. It decomposes into sodium sulfide and sodium sulfate when heated, and gradually oxidizes to sodium sulfate when placed in air. In nature, there are three forms of anhydrous sodium sulfite, sodium sulfite and sodium sulfite, among which anhydrous sodium sulfite is the least susceptible to oxidation. Sodium sulfite can be obtained by passing sulfur dioxide into a sodium hydroxide solution, and when the sulfur dioxide is excessive, sodium hydrogen sulfite is formed. Alternatively, sulfur dioxide gas is introduced into the sodium carbonate solution, and after saturation, sodium carbonate solution is added, and crystallized to obtain crystals of heptahydrate, which are heated and dehydrated to obtain an anhydride.
Sodium sulfite can be used as a developer, preparation of cellulose sulfite, preparation of sodium thiosulfate, preservatives for dried fruits and meats, deoxidizers in the printing and dyeing industry, and as a reducing chemical agent for chemical and laboratory applications. Production and synthesis.
Basic Information
Anhydrous sodium sulfite, or as a white crystalline powder ; odorless. This product is soluble in water, in ethanol, very slightly soluble, almost insoluble in diethyl ether. Was dissolved in water (0 ℃, 12.54g / 100ml water; 80 ℃ when 28.3g / 100ml water) at 33.4 deg.] Ca solubility of up to about 28% alkaline aqueous solution, PH value of about 9 to 9.5. Slightly soluble in alcohol, insoluble in liquid chlorine , ammonia . Easily oxidized in air over sodium sulfate , sodium sulfide when the temperature is decomposed into. To strengthen the reducing agent, and generated sulfur dioxide and sodium bisulfite , with a strong acid to form the corresponding salt.
index
| Indicator name |
Superior product |
First grade |
Qualified product |
| Exterior |
White crystal powder |
| Mass fraction of sodium sulfite (Na2SO3) /% ≥ |
97.0 |
96.0 |
93.0 |
| Iron (Fe) /% ≤ |
0.003 |
0.005 |
0.02 |
| Water insoluble matter /% ≤ |
0.02 |
0.03 |
0.05 |
| Free base (calculated as Na2CO3) /% ≤ |
0.10 |
0.40 |
0.60 |
| Sulfate (Na2SO4) /% ≤ |
2.5 |
One |
One |
| Chloride (NaCl) /% ≤ |
0.10 |
One |
One |
use
1. Anhydrous sodium sulfite is used for film development
2, the chemical industry as a reducing agent and sulfonating agent;
3. Dechlorination and bleaching agents for the printing and dyeing industry;
4. Stabilizers for chemical fibers, etc.
Storage and transportation attention
Store in a cool, dry and ventilated warehouse. Keep away from the heat of the fire. The package is sealed and must not be in contact with air. Do not store and transport with oxidants, strong acids and hazardous materials. This product has deliquescence, not long storage. Protect from rain and sun exposure when transporting.
