|
Mercury(I) Sulfide
Mercury(I) sulfide or mercurous sulfide is a hypothetical chemical compound of mercury and sulfur, with elemental formula . Its existence has been disputed; it may be stable below 0 °C or in suitable environments, but is unstable at room temperature, decomposing into metallic mercury and mercury(II) sulfide (mercuric sulfide, cinnabar).Ronald L. Rich (2007): "Zinc through Mercury". In: ''Inorganic Reactions in Water'', pages 289–306. Published by Springer. History This compound was described in the 19th century by Berzelius as a black precipitate obtained by passing hydrogen sulfide through solutions of mercury(I) salts.Berzelius, ''Lehrb.''Berzelius: ''Archiv des Apotheker Vereins im nördlichen Deutschland''.Charles Baskerville (1903): "Mercurous sulphide". ''Journal of the American Chemical Society'', volume 25, issue 8, pages 799–800. As of 1825, the London Pharmacopoeia listed a compound called "Ethiops-mineral" or ''Hydrargyri Sulphuretum Nigrum'' ("black s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italian People
, flag = , flag_caption = The national flag of Italy , population = , regions = Italy 55,551,000 , region1 = Brazil , pop1 = 25–33 million , ref1 = , region2 = Argentina , pop2 = 20–25 million , ref2 = , region3 = United States , pop3 = 17-20 million , ref3 = , region4 = France , pop4 = 1-5 million , ref4 = , region5 = Venezuela , pop5 = 1-5 million , ref5 = , region6 = Paraguay , pop6 = 2.5 million , region7 = Colombia , pop7 = 2 million , ref7 = , region8 = Canada , pop8 = 1.5 million , ref8 = , region9 = Australia , pop9 = 1.0 million , ref9 = , region10 = Uruguay , pop10 = 1.0 million , r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Thiosulfate
Sodium thiosulfate (sodium thiosulphate) is an inorganic compound with the formula . Typically it is available as the white or colorless pentahydrate, . The solid is an efflorescent (loses water readily) crystalline substance that dissolves well in water. Sodium thiosulfate is used in gold mining, water treatment, analytical chemistry, the development of silver-based photographic film and prints, and medicine. The medical uses of sodium thiosulfate include treatment of cyanide poisoning and pityriasis. It is on the World Health Organization's List of Essential Medicines. Uses Sodium thiosulfate is used predominantly in industry. For example, it is used to convert dyes to their soluble colorless forms, which are called leuco. It is also used to bleach "wool, cotton, silk, ...soaps, glues, clay, sand, bauxite, and... edible oils, edible fats, and gelatin." Medical uses Sodium thiosulfate is used in the treatment of cyanide poisoning. Other uses include topical treatment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Joseph Scherer
Johann Joseph Scherer (18 March 1814 – 17 February 1869) was a German physician and chemist born in Aschaffenburg. In 1836 he graduated from the University of Würzburg, where he studied medicine, chemistry, geology and mineralogy. From 1836 to 1838 he practiced medicine in Wipfeld, afterwards relocating to the University of Munich, where he resumed his studies in chemistry. In 1840 he worked in the laboratory of Justus Liebig (1803-1873) at Giessen, returning to Würzburg in 1842 as a professor of organic chemistry. During his career at Würzburg, he held the title of professor in the departments of general, inorganic, and pharmacological chemistry, also attaining directorship of the Medical Institute for Chemistry and Hygiene. Scherer was a pioneer of clinical chemistry, and is remembered for applying his knowledge of chemistry to problems in the field of medicine. He made contributions in the study of urine and blood in pathological conditions, and in 1843 and 1851 demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury(I) Nitrate
Mercury(I) nitrate is a inorganic compound, a salt of mercury and nitric acid with the formula Hg2(NO3)2. A yellow solid, the compound is used as a precursor to other complexes of Hg22+ complexes.The structure of the hydrate has been determined by X-ray crystallography. It consists of a 2O-Hg-Hg-OH2sup>2+ center, with a Hg-Hg distance of 254 pm. Reactions Mercury(I) nitrate is formed when elemental mercury is combined with ''dilute'' nitric acid (concentrated nitric acid will yield mercury(II) nitrate). Mercury(I) nitrate is a reducing agent which is oxidized upon contact with air. Mercuric nitrate reacts with elemental mercury to form mercurous nitrate. Solutions of mercury(I) nitrate are acidic due to slow reaction with water: :Hg2(NO3)2 + H2O ⇌ Hg2(NO3)(OH) + HNO3 Hg2(NO3)(OH) forms a yellow precipitate. If the solution is boiled or exposed to light, mercury(I) nitrate undergoes a disproportionation In chemistry, disproportionation, sometimes called dismutation, is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical synt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Base
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH3 is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane (Me3B) is a Lewis acid as it is capable of accepting a lone pair. In a Lewis adduct, the Lewis acid and base share an electron pair furnished by the Lewis base, forming a dative bond. In the context of a specific chemical reaction between NH3 and Me3B, a lone pair from NH3 will form a dative bond with the empty orbital of Me3B to form an adduct NH3•BMe3. The terminology refers to the contributions of Gilbert N. Lewis. From p. 142: "We are inclined to think of substances as pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klaus Brodersen
Klaus is a German, Dutch and Scandinavian given name and surname. It originated as a short form of Nikolaus, a German form of the Greek given name Nicholas. Notable persons whose family name is Klaus * Billy Klaus (1928–2006), American baseball player * Chris Klaus (born 1973), American entrepreneur * Frank Klaus (1887–1948), German-American boxer, 1913 Middleweight Champion *Fred Klaus (born 1967), German footballer * Josef Klaus (1910–2001), Chancellor of Austria 1966–1970 *Karl Ernst Claus (1796–1864), Russian chemist *Václav Klaus (born 1941), Czech politician, former President of the Czech Republic * Walter K. Klaus (1912–2012), American politician and farmer Notable persons whose given name is Klaus *Brother Klaus, Swiss patron saint *Klaus Augenthaler (born 1957), German football player and manager *Klaus Badelt (born 1967), German composer *Klaus Barbie (1913–1991), German SS-Hauptsturmführer and Holocaust Perpetrator *Klaus Bargsten (1911–2000), G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimercury(I) Ion
Mercury polycations are polyatomic cations that contain only mercury (element), mercury atoms. The best known example is the ion, found in mercury(I) (mercurous) compounds. The existence of the metal–metal bond in Hg(I) compounds was established using X-ray spectroscopy, X-ray studies in 1927 and Raman spectroscopy in 1934 making it one of the earliest, if not the first, metal–metal covalent bonds to be characterised. Other mercury polycations are the linear and ions, and the triangular ion and a number of chain and layer polycations. Mercury(I) The best known polycation of mercury is , in which mercury has a formal oxidation state of +1. The ion was perhaps the first metal-metal bonded species confirmed. The presence of the ion in solution was shown by Ogg in 1898. In 1900, Baker showed the presence of HgCl dimers in the vapour phase. The presence of units in the solid state was first determined in 1926 using X-ray diffraction. The presence of the metal-metal bond in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions. The component ions in a salt compound can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as fluoride (F−), or polyatomic, such as sulfate (). Types of salt Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called ''alkali salts'' and salts that produce hydrogen ions when dissolved in water are called ''acid salts''. ''Neutral salts'' are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabolites, peptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury(I) Chloride
Mercury(I) chloride is the chemical compound with the formula Hg2Cl2. Also known as the mineral calomel (a rare mineral) or mercurous chloride, this dense white or yellowish-white, odorless solid is the principal example of a mercury(I) compound. It is a component of reference electrodes in electrochemistry. History The name calomel is thought to come from the Greek ''καλός'' "beautiful", and ''μέλας'' "black"; or ''καλός'' and ''μέλι'' "honey" from its sweet taste. The "black" name (somewhat surprising for a white compound) is probably due to its characteristic disproportionation reaction with ammonia, which gives a spectacular black coloration due to the finely dispersed metallic mercury formed. It is also referred to as the mineral ''horn quicksilver'' or ''horn mercury''. Calomel was taken internally and used as a laxative, for example to treat George III in 1801, and disinfectant, as well as in the treatment of syphilis, until the early 20th century. Unti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
