sodium hydrosulfite - is an inorganic compound, a metal salt of an acidic sodium and sulphurous acid, a preservative (E222), and an antioxidant.It has bleaching properties.It has the following chemical formula: NaHSO3.
physical properties of sodium hydrosulfite:
1. It is a white powder, having faint grayish hue.
2. The molar mass of 104,061 g / mol, density - 1.48 g / santimetr³.
3. Melting point is 150 degrees Celsius.
4. It dissolves in water (H2O) and dilute alkalis.
chemical properties of sodium hydroxide:
1. decompose when heated:
2NaHSO3 (sodium hydrosulfite) = Na2SO3 (sodium sulfite) + SO2 (sulfur dioxide, is released as a gas) + H2O (water)
2.Decomposed acids:
NaHSO3 + HCl (hydrochloric acid) = NaCl (sodium chloride) + SO2 (sulfur dioxide) + H2O (water)
3. decomposed alkalis:
NaHSO3 + NaOH (hydroxide) = Na2SO3 (sodium sulfite)+ H2O (water)
4. oxidized by oxygen:
4NaHSO3 + O2 = 2Na2SO4 (sodium sulfate) + 2SO2 (sulfur dioxide, escapes) + H2O (water)
How to get sodium hydrosulfite?
This compound can be obtained in the following ways: 1.
By reacting sodium hydroxide with sulfur dioxide:
NaOH (sodium base) + SO2 (sulfur oxide) = NaHSO3 (sodium bisulfite)
2. By the reaction (at room temperature)sodium dithionite with water and hydrochloric acid:
2Na2S2O4 (sodium dithionite) + H2O (water) + HCl (hydrochloric acid) = 2NaHSO3 (sodium hydrosulfite) + S (sulfur precipitates as precipitate) + NaCl (sodium chloride)
3. With a reaction in which sodium dithionite reacts, water and oxygen:
2Na2S2O4 (sodium dithionite in diluted form) + 2H2O (water) + O2 (oxygen) = 4NaHSO3 (sodium hydrosulfite)
Application sodium hydrosulfite:
- light, chemical and other industries;
- in the food industry it is used as an antioxidant or a preservative;
- used in almost all wines intended for export (sodium hydrosulfite chemical properties, in this case helps to prevent oxidation and preserve the taste of the drink);
- is used for canning fruits to fight germs and prevent browning;
- and bleached for dyeing various fabrics used as a preservative;
- for removing reactive dyes in the dyeing process of cotton;
- in dyeing polyester for restorative treatment;
- as the preservative in the bleaching of fabrics and as a reducing agent for vat dyes;
- in biochemical engineering is used in order to maintain the anaerobic conditions in the reactor.
Toxic if sodium hydrosulfite to humans?
substance is considered by us in excessive concentrations can cause severe allergic reactions.With nineteen eighties NaHSO3 (as potassium bisulfite, E 228) is prohibited in the United States for use on raw fruits and vegetables after a number of cases, death.Sodium bisulfite causes various diseases of the digestive system.According to the EU directive on hazardous substances to humans, the additive E 222 belongs to the group of hazardous chemicals.In Ukraine, the Russian Federation and the substance is permitted for use only with strict observance of technology.
use of sodium hydrogen sulphate in the food industry
This material is used in the food industry, called E 222. This nutritional supplement synthetic origin having a high level of risk.In the long systematic use causes serious harm to the body.Due to the property inhibit reproduction and growth of microorganisms and bacteria used as an antioxidant and a preservative.In the acidic environment of sodium hydrosulfite is decomposed into sulfur-containing compounds and sulfur itself.
First aid measures in case of poisoning
recommended rest and keep warm, dry and clean clothes and fresh air.Skin and eyes should be rinsed with cold water.With burns must impose aseptic bandage.Next, call an ambulance.
