sulfur distributed in the earth's crust, among other elements takes sixteenth place.It is found in the free state, and in bound form.Non-metallic properties are characteristic of this chemical element.Its Latin name «Sulfur», is denoted by S. The element belongs to various ion compounds containing oxygen and / or hydrogen forms many substances belonging to the classes of acid salts and multiple oxides each of which may be referred to as a sulfur oxide with the addition ofcharacters representing the valency.Oxidation state, which it displays in different compounds 6, 4, 2, 0, -1, -2.Known sulfur oxides with different oxidation states.The most common - it dioxide and sulfur trioxide.Less well known are carbon monoxide, sulfur and higher (except SO3) and the lower oxides of this element.
monoxide sulfur
inorganic compounds called sulfur oxide II, SO, in appearance the substance is a colorless gas.In contact with water it does not dissolve, and react with it.This is a very rare compound that is found only in the rarefied gas environment.SO thermodynamically unstable molecule is converted initially S2O2, (called disulfur sulfur dioxide or peroxide).Because of the rare occurrence of sulfur monoxide in our atmosphere and low stability of the molecule are difficult to fully identify the danger of that substance.But in the condensed or more concentrated form oxide it turns into peroxide which is relatively non-toxic and corrosive.This compound is also highly flammable (reminiscent of this property methane), is obtained from the combustion of sulfur dioxide - a toxic gas.Sulfur oxide was found around 2 Io (one of Jupiter's moons) in the atmosphere of Venus and in the interstellar medium.It is assumed that on Io, it is the result of volcanic and photochemical processes.Basic photochemical reactions are as follows: O + S2 → S + SO and SO2 → SO + O.
Sulphur dioxide
sulfur oxide IV, or sulfur dioxide (SO2) is a colorless gas with a suffocating pungent odor.At a temperature of minus 10 C, it goes into a liquid state and at a temperature of minus 73 C solidifies.At 20 ° C in 1 liter of water dissolves approximately 40 volumes of SO2.
This sulfur oxide dissolves in water, forms sulfurous acid, as is its anhydride: SO2 + H2O ↔ H2SO3.
It interacts with bases and basic oxides: 2NaOH + SO2 → Na2SO3 + H2O and SO2 + CaO → CaSO3.
for sulfur dioxide and characteristic properties of the oxidant and reductant.It is oxidized by atmospheric oxygen to sulfur trioxide in the presence of a catalyst: SO2 + O2 → 2SO3.With strong reducing agents such as hydrogen sulfide, plays the role of an oxidant: H2S + SO2 + H2O → S.
Sulphur dioxide is used in industry mainly for the production of sulfuric acid.Sulphur dioxide is produced by burning sulfur or iron pyrites: 11O2 + 4FeS2 → 2Fe2O3 + 8SO2.
sulfuric anhydride
sulfur oxides VI, or sulfur trioxide (SO3) is an intermediate product, and has no independent significance.In appearance it is a colorless liquid.It boils at a temperature of 45 C and below 17 C turns into a white crystalline mass.This higher sulfur oxide (with a degree of oxidation of the sulfur atom + 6) at different hygroscopicity.With water, it forms sulfuric acid: SO3 + H2O ↔ H2SO4.Dissolved in water, emits large amounts of heat and, if not add gradually, once a large number of oxide, it may explode.Sulfur trioxide is readily soluble in concentrated sulfuric acid to form oleum.The content of SO3 in the oleum is 60%.For this sulfur compound is characterized by all properties of an acidic oxide.
higher and lower sulfur oxides
higher sulfur oxides are a group of chemical compounds with the formula SO3 + x, where x can be 0 or 1. The monomeric oxide SO4 contain peroxo (OO) and is characterized asoxide SO3, the degree of oxidation of sulfur 6.This sulfur oxide can be produced at low temperatures (below 78 C) in the reaction SO3 and atomic oxygen or photolysis of SO3 in the mixture with ozone.
Lower sulfur oxides constitute a group of chemical compounds, which comprises:
- SO (sulfur dioxide and its dimer S2O2);
- S2O;
- sulfur monoxides SnO (are cyclic compounds consisting of rings formed by sulfur atoms, wherein n can be from 5 to 10);
- S7O2;
- polymeric sulfur oxides.
interest to lower oxides of sulfur increased.This is due to the need to study their content in terrestrial and extraterrestrial atmospheres.
