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Praseodymium Hydroxide
Praseodymium(III) hydroxide is an inorganic compound with a chemical formula Pr(OH)3. Production The reaction between ammonia water and praseodymium(III) nitrate produces praseodymium(III) hydroxide:《无机化合物制备手册》. 朱文祥 主编. 化学工业出版社. P98~99. 【III-103】氢氧化镨（praseodymium hydroxide） : Pr(NO3)3 + 3 NH3·H2O → Pr(OH)3↓ + 3 NH4NO3 Chemical properties Praseodymium(III) hydroxide can react with acid and produce praseodymium Praseodymium is a chemical element with the symbol Pr and the atomic number 59. It is the third member of the lanthanide series and is considered to be one of the rare-earth metals. It is a soft, silvery, malleable and ductile metal, valued for ... salts: : Pr(OH)3 + 3 H+ → Pr3+ + 3 H2O, for example; Pr(OH)3 + 3CH3COOH forms Pr(CH3CO2)3 + 3H2O; Praseodymium(III) hydroxide + Acetic acid forms praseodymium(III) acetate and water. References {{hydroxides Praseodymium compounds Hydroxides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium(III) Oxide
Praseodymium(III) oxide, praseodymium oxide or praseodymia is the chemical compound composed of praseodymium and oxygen with the formula Pr2O3. It forms light green hexagonal crystals. Praseodymium(III) oxide crystallizes in the manganese(III) oxide or bixbyite structure. Uses Praseodymium(III) oxide can be used as a dielectric in combination with silicon. Praseodymium-doped glass, called didymium glass, turns yellow and is used in welding goggles because it blocks infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from aroun ... radiation. Praseodymium(III) oxide is also used to color glass and ceramics yellow. For coloring ceramics, also the very dark brown mixed-valence compound praseodymium(III,IV) oxide, Pr6O11, is used. References {{DEFAULTSORT:Praseodymium(Iii) Oxide Pras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerium(III) Hydroxide
Cerium(III) hydroxide is a hydroxide of the rare-earth metal The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silve ... cerium. It is a pale white powder with the chemical formula Ce(OH)3.[\atop] 2Ce(OH)3(v) + 3H2 References {{Hydroxides Hydroxides Cerium(III) compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium(III) Hydroxide
Neodymium(III) hydroxide is an insoluble inorganic compound with the chemical formula Nd(OH)3. Production Neodymium(III) nitrate and ammonia water will react to produce neodymium(III) hydroxide《无机化合物制备手册》. 朱文祥 主编. 化学工业出版社. 【III-119】氢氧化钕（neodymium hydroxide） : Nd(NO3)3 + 3 NH3·H2O → Nd(OH)3↓ + 3 NH4NO3 If the amount of Nd(NO3)3 is 40g/L, the amount of ammonia water needed is 0.50 mol/L. The ammonia water is mixed into the Nd(NO3)3 solution at the speed of 1.5mL/min, and polyethylene glycol is used to control pH. The process will produce neodymium(III) hydroxide powder with grain size ≤1μm. 刘治平, 王晓铁. 氢氧化镧和氢氧化钕微粉的制备 《稀土》. Vol.25 No.3 Jun.2004 Chemical properties Neodymium(III) hydroxide can react with acid and produce neodymium salts: : Nd(OH)3 + 3 H+ → Nd3+ + 3 H2O For example, to create neodymium acetate with neodymium(III) hydroxide: :Nd(OH)3 + 3CH3COOH � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon ( graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called '' empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of ato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia Water
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3(aq). Although the name ammonium hydroxide suggests an alkali with composition , it is actually impossible to isolate samples of NH4OH. The ions and OH− do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions. Basicity of ammonia in water In aqueous solution, ammonia deprotonates a small fraction of the water to give ammonium and hydroxide according to the following equilibrium: : NH3 + H2O NH4+ + OH−. In a 1 M ammonia solution, about 0.42% of the ammonia is converted to ammonium, equivalent to pH = 11.63 because H4+�= 0.0042 M, H−�= 0.0042 M, H3�= 0.9958 M, and pH = 14 + log10 H−�= 11.62. The base ionization constant is : ''K''b = H4+OH−] / H3= 1.77. Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium(III) Nitrate
Praseodymium(III) nitrate is a green-colored chemical compound with the chemical formula Pr(NO3)3. It is very hygroscopic and forms a hexahydrate. It is soluble in polar solvents. Uses Praseodymium(III) nitrate is used in fluorescent display tubes and phosphors. It is also used in the ultrasonic synthesis of praseodymium molybdate In chemistry a molybdate is a compound containing an oxoanion with molybdenum in its highest oxidation state of 6. Molybdenum can form a very large range of such oxoanions which can be discrete structures or polymeric extended structures, althoug .... It also plays a role in the preparation in lanthanide oxysulfides. References {{Nitrates Praseodymium compounds Nitrates Phosphors and scintillators ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a ''transaction''. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, Andreas Reuter and Theo Härder coined the acronym ''ACID'', building on earlier work by Jim Gray who named atomicity, consistency, and durability, but not isolation, when characterizing the transaction concept. These four properties are the major guarantees of the transaction paradigm, which has influenced many aspects of development in database systems. According to Gray and Reuter, the IBM In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium
Praseodymium is a chemical element with the symbol Pr and the atomic number 59. It is the third member of the lanthanide series and is considered to be one of the rare-earth metals. It is a soft, silvery, malleable and ductile metal, valued for its magnetic, electrical, chemical, and optical properties. It is too reactive to be found in native form, and pure praseodymium metal slowly develops a green oxide coating when exposed to air. Praseodymium always occurs naturally together with the other rare-earth metals. It is the sixth-most abundant rare-earth element and fourth-most abundant lanthanide, making up 9.1 parts per million of the Earth's crust, an abundance similar to that of boron. In 1841, Swedish chemist Carl Gustav Mosander extracted a rare-earth oxide residue he called didymium from a residue he called "lanthana", in turn separated from cerium salts. In 1885, the Austrian chemist Baron Carl Auer von Welsbach separated didymium into two elements that gave salts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium Compounds
Praseodymium compounds are compounds formed by the lanthanide metal praseodymium (Pr). In these compounds, praseodymium generally exhibits the +3 oxidation state, such as PrCl3, Pr(NO3)3 and Pr(CH3COO)3. However, compounds with praseodymium in the +2 and +4 oxidation states, and unlike other lanthanides, the +5 oxidation state, are also known. Oxides Praseodymium can form oxides in many different ways, although the only oxides that are stable at room temperature are Pr2O3, Pr6O11 and PrO2. Praseodymium(III) oxide is a green powder that forms hexagonal crystals, and crystallizes in the manganese(III) oxide or bixbyite structure. Praseodymium(IV) oxide can be produced by boiling Pr6O11 in water or acetic acid: zh, 《无机化学丛书》.第七卷 钪 稀土元素. 科学出版社. 1.3.4 氧化态+4的化合物., translation=Inorganic Chemistry Series. Volume VII Rare Earth Elements. Science Press. 1.3.4 Compounds with oxidation state +4. P193~195 : Pr6O11 + 3 H2O → 4 PrO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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