sulfur oxides (sulfur dioxide, sulfur dioxide, sulfur dioxide) - is a colorless gas with in normal conditions a sharp characteristic odor (similar to the smell of an illuminated matches).Liquefied under pressure at room temperature.Sulphur dioxide is soluble in water, forming unstable sulfuric acid.It also dissolves in sulfuric acid and ethanol.This is one of the main components that make up the volcanic gases.
How to get sulfur dioxide
Getting SO2 - sulfur dioxide - industrial method consists in burning sulfur or roasting of sulphides (used mainly pyrite).
4FeS2 (pyrite) + 11O2 = 2Fe2O3 (iron oxide) + 8SO2 (sulfur dioxide).
in laboratory conditions sulfur dioxide can be produced by the action of strong acids hydrosulfites and sulphites.This yields sulphurous acid immediately decomposes into water and sulfur dioxide.For example:
Na2SO3 (sodium sulfite) + H2SO4 (sulfuric acid) = Na2SO4 (sodium sulphate) + H2SO3 (sulfurous acid).
H2SO3 (sulfurous acid) = H2O (water) + SO2 (sulfur dioxide).
third method of producing sulfur dioxide is the impact of concentrated sulfuric acid under heating at less active metals.For example: Cu (copper) + 2H2SO4 (sulfuric acid) = CuSO4 (copper sulfate) + SO2 (sulfur dioxide) + 2H2O (water).
chemical properties of sulfur dioxide
formula for sulfur dioxide - SO3.This substance belongs to the acidic oxides.
1. The sulfur dioxide dissolves in water, thereby forming sulphurous acid.Under normal conditions, this reaction is reversible.
SO2 (sulfur dioxide) + H2O (water) = H2SO3 (sulfurous acid).
2. With alkali sulfites, sulfur dioxide forms.For example: 2NaOH (Sodium hydroxide) + SO2 (sulfur dioxide) = Na2SO3 (sodium sulfite) + H2O (water).
3. Reactivity of sulfur dioxide is sufficiently large.Most expressed reduction properties of sulfur dioxide.In such reactions the degree of sulfur oxidation increases.For example: 1), SO2 (sulfur dioxide) + Br2 (bromine) + 2H2O (water) = H2SO4 (sulfuric acid) 2HBr + (hydrogen bromide);2) 2SO2 (sulfur dioxide) + O2 (oxygen) 2SO3 = (sulfite);3) 5SO2 (sulfur dioxide) + 2KMnO4 (potassium permanganate) + 2H2O (water) 2H2SO4 = (Sulfuric acid) + 2MnSO4 (manganese sulphate) + K2SO4 (potassium sulfate).
latter reaction - an example of a high-quality response to SO2 and SO3.It occurs bleaching solution violet).
4. In the context of the presence of strong reducing sulfur dioxide can exhibit oxidative properties.For example, in order to extract the metallurgical industry sulfur from flue gases, the sulfur dioxide recovery using carbon monoxide (CO): SO2 (sulfur dioxide) + 2CO (carbon monoxide) = 2CO2 (carbon dioxide) + S (sulfur).Also
oxidative properties of this substance is used to obtain fosfornovaristoy of acids: PH3 (phosphine) + SO2 (sulfur dioxide) = H3PO2 (fosfornovaristaya acid) + S (sulfur).
Where to apply sulfur dioxide
mainly sulfur dioxide is used to produce sulfuric acid.Also it is used as a preservative (E-220) in the manufacture of soft drinks (wine and other drinks average price category).Due to the property of this gas to kill various microorganisms, they fumigate warehouses and vegetable store.In addition, the sulfur dioxide is used for bleaching wool, silk, straw (those materials which can not be bleached with chlorine).In the laboratories of the sulfur dioxide is used as a solvent in order to obtain different salts of sulfurous acid.
Sulphur dioxide has strong toxic properties.Symptoms of poisoning - a cough, runny nose, hoarseness, a kind of taste in the mouth, severe sore throat.Inhalation of sulfur dioxide in high concentrations, there is difficulty in swallowing and choking, speech disorder, nausea and vomiting, may develop acute pulmonary edema.
MPC of sulfur dioxide:
- in the room - 10 mg / m³;
- average daily maximum one-time in the air - 0.05 mg / m³.
sensitivity to sulfur dioxide in individual people, plants and animals are different.For example, among the most resistant trees oak and birch, and the least - spruce and pine.