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Perbromate
In chemistry, the perbromate ion is the anion having the chemical formula . It is an oxyanion of bromine, the conjugate base of perbromic acid, in which bromine has the oxidation state +7. Unlike its chlorine () and iodine () analogs, it is difficult to synthesize. It has tetrahedral molecular geometry. The term perbromate also refers to a compound that contains the anion or the functional group. The perbromate ion is a strong oxidizing agent. The reduction potential for the / Br− couple is +0.68 V at pH 14. This is comparable to selenite's reduction potential. Synthesis Attempted syntheses of perbromates were unsuccessful until 1968, when it was finally obtained by the beta decay of selenium-83 in a selenate salt: : → + β− Subsequently, it was successfully synthesized again by the electrolysis of , although only in low yield. Later, it was obtained by the oxidation of bromate with xenon difluoride. Once perbromates are obtained, perbromic acid ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromine
Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek (bromos) meaning "stench", referring to its sharp and pungent smell. Elemental bromine is very reactive and thus does not occur as a native element in nature but it occurs in colourless soluble crystalline mineral halide salts, analogous to table salt. In fact, bromine and all the halogens are so reactive that they form bonds in pairs—never in single atoms. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its accumulation in the oceans. Commer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diperiodatonickelate
The periodatonickelates are a series of anions and salts of nickel complexed to the periodate anion. The diperiodatonickelates with nickel in the +4 oxidation state are powerful oxidising agents that are capable of oxidising bromate to perbromate. Sodium nickel periodate, NaNiIO6·0.5H2O and potassium nickel periodate, KNiIO6·0.5H2O were discovered in 1949 by P. Ray and B. Sarma. These double salts are coloured dark purple. The salts were made by oxidising nickel sulfate mixed with potassium periodate (or sodium periodate) with the alkali persulfate salt in boiling water. Similar solids exist for other alkalis such as RbNiIO6·0.5H2O ,CsNiIO6·0.5H2O and NH4NiIO6·0.5H2O. The crystalline salts are insoluble in water, acids or bases. Ozone can also be used as the oxidiser. The colour is due to absorbance of visible light shorter than 800 nm, with a peak at 540 nm. The crystal structure of all the solids has space group ''P''312. It contains layers of hexagon arrangemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perbromic Acid
The compound perbromic acid is the inorganic compound with the formula HBrO4. It is an oxoacid of bromine. Perbromic acid is unstable and cannot be formed by displacement of chlorine from perchloric acid, as periodic acid is prepared; it can only be made by protonation of the perbromate ion. Perbromic acid is a strong acid and strongly oxidizing. It is the most unstable of the halogen(VII) oxoacids. It decomposes rapidly on standing to bromic acid and oxygen. It reacts with bases to form perbromate salts. See also *Perbromate In chemistry, the perbromate ion is the anion having the chemical formula . It is an oxyanion of bromine, the conjugate base of perbromic acid, in which bromine has the oxidation state +7. Unlike its chlorine () and iodine () analogs, it is dif ... Further reading * {{Inorganic-compound-stub Halogen oxoacids Hydrogen compounds Oxidizing agents Oxidizing acids Perbromates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypobromite
The hypobromite ion, also called alkaline bromine water, is BrO−. Bromine is in the +1 oxidation state. The Br–O bond length is 1.82 Å. Hypobromite is the bromine compound analogous to hypochlorites found in common bleaches, and in immune cells. In many ways, hypobromite functions in the same manner as hypochlorite, and is also used as a germicide and antiparasitic in both industrial applications, and in the immune system. Preparation Hypobromite salts form upon treating bromine with aqueous alkali, such as sodium or potassium hydroxide. At 20 °C the reaction is rapid. : Br2 + 2 OH−(aq) → Br− + BrO− + H2O In this reaction the bromine disproportionates (some undergoes reduction and some oxidation) from oxidation state 0 (Br2) to oxidation state −1 (Br−) and oxidation state +1 (BrO−). Sodium hypobromite can be isolated as an orange solid. A secondary reaction, where hypobromite spontaneously disproportionates to bromide (bromine oxidation state −1) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromate
The bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, (), and potassium bromate, (). Bromates are formed many different ways in municipal drinking water. The most common is the reaction of ozone and bromide: : Br + → BrO Electrochemical processes, such as electrolysis of brine without a membrane operating to form hypochlorite, will also produce bromate when bromide ion is present in the brine solution. Photoactivation (sunlight exposure) will encourage liquid or gaseous bromine to generate bromate in bromide-containing water. In laboratories bromates can be synthesized by dissolving in a concentrated solution of potassium hydroxide (KOH). The following reactions will take place (via the intermediate creation of hypobromite): : + 2 OH− → Br + BrO + :3 BrO → BrO + 2 Br Human health issues Bromate in drinking water is undesirable because it is a suspected human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypobromite Ion Space Fill
The hypobromite ion, also called alkaline bromine water, is BrO−. Bromine is in the +1 oxidation state. The Br–O bond length is 1.82 Å. Hypobromite is the bromine compound analogous to hypochlorites found in common bleaches, and in immune cells. In many ways, hypobromite functions in the same manner as hypochlorite, and is also used as a germicide and antiparasitic in both industrial applications, and in the immune system. Preparation Hypobromite salts form upon treating bromine with aqueous alkali, such as sodium or potassium hydroxide. At 20 °C the reaction is rapid. : Br2 + 2 OH−(aq) → Br− + BrO− + H2O In this reaction the bromine disproportionates (some undergoes reduction and some oxidation) from oxidation state 0 (Br2) to oxidation state −1 (Br−) and oxidation state +1 (BrO−). Sodium hypobromite can be isolated as an orange solid. A secondary reaction, where hypobromite spontaneously disproportionates to bromide (bromine oxidation state −1) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space-filling Model
In chemistry, a space-filling model, also known as a ''calotte model'', is a type of three-dimensional (3D) molecular model where the atoms are represented by spheres whose radii are proportional to the radii of the atoms and whose center-to-center distances are proportional to the distances between the atomic nuclei, all in the same scale. Atoms of different chemical elements are usually represented by spheres of different colors. Space-filling calotte models are also referred to as CPK models after the chemists Robert Corey, Linus Pauling, and Walter Koltun, who over a span of time developed the modeling concept into a useful form. They are distinguished from other 3D representations, such as the ball-and-stick and skeletal models, by the use of the "full size" space-filling spheres for the atoms. The models are tactile and manually rotatable. They are useful for visualizing the effective shape and relative dimensions of a molecule, and (because of the rotatability) th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium-83
Selenium (34Se) has six natural isotopes that occur in significant quantities, along with the trace isotope 79Se, which occurs in minute quantities in uranium ores. Five of these isotopes are stable: 74Se, 76Se, 77Se, 78Se, and 80Se. The last three also occur as fission products, along with 79Se, which has a half-life of 327,000 years,The half-life of 79Se and 82Se, which has a very long half-life (~1020 years, decaying via to 82Kr) and for practical purposes can be considered to be stable. There are 23 other unstable isotop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromide Ion
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, as it reacts with all other elements except for the light inert gases. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb meaning 'flow' gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist Henri Moissan isolate elemental fluorine using low-temperature electrolysis, a process still employed for moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
