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Bismuth(III) Iodide
Bismuth(III) iodide is the inorganic compound with the formula Bi I3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis. Bismuth(III) iodide adopts a distinctive crystal structure, with iodide centres occupying a hexagonally closest-packed lattice, and bismuth centres occupying either none or two-thirds of the octahedral holes (alternating by layer), therefore it is said to occupy one third of the total octahedral holes. Synthesis Bismuth(III) iodide forms upon heating an intimate mixture of iodine and bismuth powder: :2Bi + 3I2 → 2BiI3 BiI3 can also be made by the reaction of bismuth oxide with aqueous hydroiodic acid: :Bi2O3(s) + 6HI(aq) → 2BiI3(s) + 3H2O(l) Reactions Since bismuth(III) iodide is insoluble in water, an aqueous solution can be tested for the presence of Bi3+ ions by adding a source of iodide such as potassium iodide. A black precipitate of bismuth(III) iodide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the pseudoelement symbol for ethyl group, ethyl. Ethanol is a Volatility (chemistry), volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. As a psychoactive depressant, it is the active ingredient in alcoholic beverages, and the second most consumed drug globally behind caffeine. Ethanol is naturally produced by the fermentation process of sugars by yeasts or via petrochemical processes such as ethylene hydration. Historically it was used as a general anesthetic, and has modern medical applications as an antiseptic, disinfectant, solvent for some medications, and antidote for methanol poisoning and ethylene glycol poisoning. It is used as a chemical solvent and in the Chemical synthesis, synthesis of orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodide
An iodide ion is I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual disability. Structure and characteristics of inorganic iodides Iodide is one of the largest monatomic anions. It is assigned a radius of around 206 picometers. For comparison, the lighter halides are considerably smaller: bromide (196 pm), chloride (181 pm), and fluoride (133 pm). In part because of its size, iodide forms relatively weak bonds with most elements. Most iodide salts are soluble in water, but often less so than the related chlorides and bromides. Iodide, being large, is less hydrophilic compared to the smaller anions. One consequence of this is that sodium iodide is highly soluble in acetone, whereas sodium chloride is not. The l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bismuth Compounds
Bismuth forms mainly trivalent and a few pentavalent compounds. Many of its chemical properties are similar to those of arsenic and antimony, although much less toxic. Oxides and sulfides At elevated temperatures, vaporized bismuth metal and oxygen combine into the yellow trioxide, . Wiberg, p. 768. Greenwood, p. 553. At temperatures above 710 °C, this (molten) oxide corrodes all known oxides and even platinum. Krüger, p. 185 It forms two series of oxyanions in basic conditions: linear, chain-polymeric ; and cubic . In , the anion forms the octamer ; in , the tetramer. The dark red bismuth(V) oxide, , is unstable, liberating gas upon heating. The compound NaBiO3 is a strong oxidant. Greenwood, p. 578. Bismuth sulfide, , occurs naturally in bismuth ores, but can be synthesized from molten bismuth and sulfur. Greenwood, pp. 559–561. Halides In oxidation state +3, bismuth forms salts with all the halogens: , , , and . All hydrolyze in water except . Bismuth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium
Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table), it occurs naturally only in combination with other elements and almost always has an oxidation state of +2. It reacts readily with air to form a thin Passivation (chemistry), passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium Salt (chemistry), salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight magnesium alloy, alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three Helium nucleus, helium nuclei to a carbon nucleus. When such stars explo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron, an import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbier Reaction
The Barbier reaction is an organometallic reaction between an alkyl halide (chloride, bromide, iodide), a carbonyl group and a metal. The reaction can be performed using magnesium, aluminium, zinc, indium, tin, samarium, barium or their salts. The reaction product is a primary, secondary or tertiary alcohol. The reaction is similar to the Grignard reaction but the crucial difference is that the organometallic species in the Barbier reaction is generated ''in situ'', whereas a Grignard reagent is prepared separately before addition of the carbonyl compound. Unlike many Grignard reagents, the organometallic species generated in a Barbier reaction are unstable and thus cannot be stored or sold commercially. Barbier reactions are nucleophilic addition reactions that involve relatively inexpensive, water insensitive metals (e.g zinc powder) or metal compounds. For this reason, it is possible in many cases to run the reaction in water, making the procedure part of green chemistry. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mukaiyama Aldol Reaction
In organic chemistry, the Mukaiyama aldol addition is an organic reaction and a type of aldol reaction between a silyl enol ether () and an aldehyde () or formate (). The reaction was discovered by Teruaki Mukaiyama in 1973. His choice of reactants allows for a crossed aldol reaction between an aldehyde and a ketone (), or a different aldehyde without self-condensation of the aldehyde. For this reason the reaction is used extensively in organic synthesis. General reaction scheme The Mukaiyama aldol addition is a Lewis acid-mediated Addition reaction, addition of enol silanes to carbonyl () compounds. In this reaction, compounds with various organic groups can be used (see educts). A basic version ( = H) without the presence of Chiral auxiliary, chiral catalysts is shown below. A Racemic mixture, racemic mix of enantiomers is built. If E–Z notation, Z- or E-enol silanes are used in this reaction a mixture of four products occurs, yielding two racemates. Whether the ''anti''-di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Iodide
Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na+) and iodide anions (I−) in a crystal lattice. It is used mainly as a nutritional supplement and in organic chemistry. It is produced industrially as the salt formed when acidic iodides react with sodium hydroxide. It is a chaotropic salt. Uses Food supplement Sodium iodide, as well as potassium iodide, is commonly used to treat and prevent iodine deficiency. Iodized table salt contains 10 ppm iodide. Organic synthesis Sodium iodide is used for conversion of alkyl chlorides into alkyl iodides. This method, the Finkelstein reaction, relies on the insolubility of sodium chloride in acetone to drive the reaction: ::R–Cl + NaI → R–I + NaCl Nuclear medicine Some radioactive iodide salts of sodium, including Na 125I and Na 131I, have rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation (chemistry)
In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant. The clear liquid remaining above the precipitated or the centrifuged solid phase is also called the supernate or supernatant. The notion of precipitation can also be extended to other domains of chemistry (organic chemistry and biochemistry) and even be applied to the solid phases (e.g. metallurgy and alloys) when solid impurities segregation (materials science), segregate from a solid phase. Supersaturation The precipitation of a compound may occur when its concentration exceeds its solubility. This can be due to temperature changes, solvent evaporation, or by mixing solvents. Precipitation occurs more rapidly from a strongly supersaturated solution. The formation of a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Iodide
Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are used. It is also used for treating skin sporotrichosis and phycomycosis. It is a supplement used by people with low dietary intake of iodine. It is administered orally. Common side effects include vomiting, diarrhea, abdominal pain, rash, and swelling of the salivary glands. Other side effects include allergic reactions, headache, goitre, and depression. While use during pregnancy may harm the baby, its use is still recommended in radiation emergencies. Potassium iodide has the chemical formula K I. Commercially it is made by mixing potassium hydroxide with iodine. Potassium iodide has been used medically since at least 1820. It is on the World Health Organization's List of Essential Medicines. Potassium iodide is available as a g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroiodic Acid
Hydroiodic acid (or hydriodic acid) is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula . It is a strong acid, in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous solutions of hydrogen iodide are usually 48% to 57% HI by mass. Preparation Reactions Hydroiodic acid reacts with oxygen in air to give iodine: : Like hydrogen halides, hydroiodic acid adds to alkenes to give alkyl iodides. It can also be used as a reducing agent, for example in the reduction of aromatic nitro compounds to anilines. Cativa process The Cativa process is a major end use of hydroiodic acid, which serves as a co-catalyst for the production of acetic acid by the carbonylation of methanol. Illicit uses Hydroiodic acid is listed as a U.S. Federal DEA List I Chemical, owing to its use as a reducing agent related to the production of methamphetamine from ephedrine or pseudoephedrine Pseudoephedrine, sold under the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bismuth Oxide
Bismuth(III) oxide is a compound of bismuth, and a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite (tetragonal, much more rare), but it is usually obtained as a by-product of the smelting of copper and lead ores. Dibismuth trioxide is commonly used to produce the " Dragon's eggs" effect in fireworks, as a replacement of red lead. Structure The structures adopted by differ substantially from those of arsenic(III) oxide, , and antimony(III) oxide, .Wells, A.F. (1984) ''Structural Inorganic Chemistry''. 5th. London, England: Oxford University Press. p.890 Bismuth oxide, has five crystallographic polymorphs. The room temperature phase, α- has a monoclinic crystal structure. There are three high temperature phases, a tetragonal β-phase, a body-centred cubic γ-phase, a cubic δ- phase and an ε-phase. The room temperature α-phase has a complex structure with layers of oxygen atoms with layers of bismut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
