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Praseodymium(III) Arsenate
Praseodymium arsenate is the arsenate salt of praseodymium, with the chemical formula of PrAsO4. It has good thermal stability. Its ferroelectric transition temperature is 52°C.Choudhary, R. N. P.. Structural and electrical properties of monoclinic praseodymium arsenic oxide (PrAsO4). ''Journal of Materials Science Letters'', 1991. 10 (8): 432-434. DOI:10.1007/BF00838340 Preparation Praseodymium arsenate be prepared by reacting sodium arsenate (Na3AsO4) and praseodymium chloride (PrCl3) in a solution:Gabisoniya, Ts. D.; Nanobashvili, E. M.. Synthesis of rare earth metal arsenates. ''Soobshcheniya Akademii Nauk Gruzinskoi SSR'' (1980), 97(2), 345-8. : Na3AsO4 + PrCl3 → 3 NaCl + PrAsO4↓ The product can also be obtained by reacting praseodymium(III,IV) oxide and diammonium hydrogen arsenate in hot dilute nitric acid in a stoichiometric Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reaction ... [...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] |
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 Subscript and superscript, subscripts and superscripts. A chemical formula is not a chemical nomenclature, 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 ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoichiometric
Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products, leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of the products can be empirically determined, then the amount of the other reactants can also be calculated. This is illustrated in the image here, where the balanced equation is: : Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. This particular chemical equation is an example of complete combustion. St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium(III,IV) Oxide
Praseodymium(III,IV) oxide is the inorganic compound with the formula that is insoluble in water. It has a cubic fluorite structure. It is the most stable form of praseodymium oxide at ambient temperature and pressure. Properties and structure adopts a cubic fluorite crystal structure, measured by XRD, TEM and SEM methods. It can be considered an oxygen deficient form of praseodymium(IV) oxide (), with the Pr ions being in a mixed valency state Pr(III) and Pr(IV). This characteristic is what gives the oxide its many useful properties for its catalytic activity. Synthesis Praseodymium oxide nanoparticles are generally produced via solid-state methods such as thermolysis, molten salt method, calcination or precipitation.Shamshi Hassan, M., Shaheer Akhtar, M., Shim, KB. et al. Morphological and Electrochemical Properties of Crystalline Praseodymium Oxide Nanorods. Nanoscale Res Lett 5, 735 (2010). https://doi.org/10.1007/s11671-010-9547-8 Practically all processes, however, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solution (chemistry)
In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. If the attractive forces between the solvent and solute particles are greater than the attractive forces holding the solute particles together, the solvent particles pull the solute particles apart and surround them. These surrounded solute particles then move away from the solid solute and out into the solution. The mixing process of a solution happens at a scale where the effects of chemical polarity are involved, resulting in interactions that are specific to solvation. The solution usually has the state of the solvent when the solvent is the larger fraction of the mixture, as is commonly the case. One important parameter of a solution is the concentration, which is a measure of the amount of solute in a given amount of solution or solvent. The term "aqueous solution" is used when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium Chloride
Praseodymium(III) chloride is the inorganic compound with the formula Pr Cl3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate. Preparation Praseodymium(III) chloride is prepared by treating praseodymium metal with hydrogen chloride:L. F. Druding, J. D. Corbett, "Lower Oxidation States of the Lanthanides. Neodymium(II) Chloride and Iodide", ''J. Am. Chem. Soc.'' 83, 2462 (1961); J. D. Corbett, ''Rev. Chim. Minerale'' 10, 239 (1973), :2 Pr + 6 HCl → 2 PrCl3 + 3 H2 It is usually purified by vacuum sublimation. Hydrated salts of praseodymium(III) chloride can be prepared by treatment of either praseodymium metal or praseodymium(III) carbonate with hydrochloric acid: :Pr2(CO3)3 + 6 HCl + 15 H2O → 2 r(H2O)9l3 + 3 CO2 PrCl3∙7H2O is a hygroscopic substance, that will not crystallize from the mother liquor unless it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Arsenate
Sodium arsenate is the inorganic compound with the formula Na3AsO4. Related salts are also called sodium arsenate, including Na2HAsO4 (disodium hydrogen arsenate) and NaH2AsO4 ( sodium dihydrogen arsenate). The trisodium salt is a white or colourless solid that is highly toxic. It is usually handled as the dodecahydrate Na3AsO4.12H2O. The compound can be obtained by neutralizing arsenic acid: :H3AsO4 + 3 NaOH → Na3AsO4 + 3 H2O The salt (as its dodecahydrate) is isomorphous with trisodium phosphate Trisodium phosphate (TSP) is the inorganic compound with the chemical formula . It is a white, granular or crystalline solid, highly soluble in water, producing an alkaline solution. TSP is used as a cleaning agent, builder, lubricant, food a ....Remy, Francis; Guerin, Henri "Radiocrystallographic study of dodecahydrate trisodium arsenate and vanadate Na3AsO4.12H2O and Na3VO4.12H2O, and some hydrates of fluorinated or hydroxylated salts of general formula: M3XO4.xMY.(10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium
Praseodymium is a chemical element with the Symbol (chemistry), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praseodymium(III) Phosphate
Praseodymium(III) phosphate is an inorganic compound with the chemical formula PrPO4. Preparation Praseodymium(III) phosphate hemihydrate can be obtained by reacting praseodymium chloride and phosphoric acid: : It can also be produced by reacting silicon pyrophosphate (SiP2O7) and praseodymium(III,IV) oxide Praseodymium(III,IV) oxide is the inorganic compound with the formula that is insoluble in water. It has a cubic fluorite structure. It is the most stable form of praseodymium oxide at ambient temperature and pressure. Properties and structure ... (Pr6O11) at 1200 °C. Properties Praseodymium(III) phosphate forms light green crystals in the monoclinic crystal system, with space group ''P21/n'' and cell parameters ''a'' = 0.676 nm, ''b'' = 0.695 nm, ''c'' = 0.641 nm, β = 103.25°, Z = 4. It forms a crystal hydrate of the composition PrPO4·''n''H2O, where n < 0.5, with light green crystals of [...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] |
Arsenate
The arsenate ion is . An arsenate (compound) is any compound that contains this ion. Arsenates are salts or esters of arsenic acid. The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As(V). Arsenate resembles phosphate in many respects, since arsenic and phosphorus occur in the same group (column) of the periodic table. Arsenates are moderate oxidizers, with an electrode potential of +0.56 V for reduction to arsenites. Occurrence Arsenates occur naturally in a variety of minerals. Those minerals may contain hydrated or anhydrous arsenates. Unlike phosphates, arsenates are not lost from a mineral during weathering. Examples of arsenate-containing minerals include adamite, alarsite, annabergite, erythrite and legrandite. Where two arsenate ions are required to balance the charge in a formula, it is called diarsenate for example trizinc diarsenate, Zn3(AsO4)2. Ions The word arsenate is derived from arsenic acid, H3AsO4. This mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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