elemental sulfur) to oxidize organic compounds or hydrogen this produces hydrogen sulfide as a waste product.Ī standard lab preparation is to treat ferrous sulfide with a strong acid in a Kipp generator:įor use in qualitative inorganic analysis, thioacetamide is used to generate HĬH 3C(S)NH 2 + H 2O → CH 3C(O)NH 2 + H 2S sulfur-reducing) bacteria generate usable energy under low-oxygen conditions by using sulfates (resp. Hydrocarbons can serve as a source of hydrogen in this process. It can also be produced by treating hydrogen with molten elemental sulfur at about 450 ☌. Hydrogen sulfide is most commonly obtained by its separation from sour gas, which is natural gas with a high content of HĢS. Hydrogen sulfide decomposes without a presence of a catalyst under atmospheric pressure around 1200 ☌ into hydrogen and sulfur. By substituting a small part of sulfur with phosphorus and using even higher pressures, it has been predicted that it may be possible to raise the critical temperature to above 0 ☌ (273 K) and achieve room-temperature superconductivity. If hydrogen sulfide is pressurized at higher temperatures, then cooled, the critical temperature reaches 203 K (−70 ☌), the highest accepted superconducting critical temperature as of 2015. The critical temperature increases with pressure, ranging from 23 K at 100 GPa to 150 K at 200 GPa. When cooled below a critical temperature this high-pressure phase exhibits superconductivity. Īt pressures above 90 GPa ( gigapascal), hydrogen sulfide becomes a metallic conductor of electricity. Hydrogen sulfide is also responsible for tarnishing on various metals including copper and silver the chemical responsible for black toning found on silver coins is silver sulfide (Ag 2S), which is produced when the silver on the surface of the coin reacts with atmospheric hydrogen sulfide. Treating metal sulfides with strong acid or electrolysis often liberates hydrogen sulfide. Lead(II) acetate paper is used to detect hydrogen sulfide because it readily converts to lead(II) sulfide, which is black. Hydrogen sulfide reacts with metal ions to form metal sulfides, which are insoluble, often dark colored solids. When exposed to air, it slowly oxidizes to form elemental sulfur, which is not soluble in water. Hydrogen sulfide and its solutions are colorless. Hydrogen sulfide is slightly soluble in water and acts as a weak acid ( p K a = 6.9 in 0.01–0.1 mol/litre solutions at 18 ☌), giving the hydrosulfide ion HS − This reaction is exploited in the Claus process, an important industrial method to dispose of hydrogen sulfide. If an excess of oxygen is present, sulfur trioxide ( SOģ) is formed, which quickly hydrates to sulfuric acid:Īt high temperatures or in the presence of catalysts, sulfur dioxide reacts with hydrogen sulfide to form elemental sulfur and water. Hydrogen sulfide burns in oxygen with a blue flame to form sulfur dioxide ( SO In general, hydrogen sulfide acts as a reducing agent, although in the presence of a base, it can act as an acid by donating a proton and forming SH −. A mixture of HĢS and air can be explosive. Hydrogen sulfide is slightly denser than air. It also occurs in volcanic gases, natural gas deposits, and sometimes in well-drawn water. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers this process is commonly known as anaerobic digestion, which is done by sulfate-reducing microorganisms. Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signalling molecule. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is stinkdamp. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. Hydrogen sulfide is a chemical compound with the formula HĢS.
0 Comments
Leave a Reply. |