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Europium(III) Arsenate
Europium(III) arsenate is an arsenate salt of europium, with the chemical formula of EuAsO4. It has good thermal stability, with its p''K''sp,c of 22.53±0.03. It is a colorless crystal with a xenotime structure. Preparation Europium(III) arsenate can be prepared by reacting sodium arsenate (Na3AsO4) in a europium(III) chloride (EuCl3) solution:Gabisoniya, Ts. D.; Nanobashvili, E. M.. Synthesis of rare earth metal arsenates. ''Soobshcheniya Akademii Nauk Gruzinskoi SSR'' (1980), 97(2), 345-8. : Na3AsO4 + EuCl3 → 3 NaCl + EuAsO4↓ Reacting europium(III) oxide (Eu2O3) with arsenic pentoxide Arsenic pentoxide is the inorganic compound with the formula As2O5. This glassy, white, deliquescent solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is ars ... (As2O5) can also obtain europium(III) arsenate. :Eu2O3 + As2O5 → 2EuAsO4 References {{Arsenates Europium(III) compounds category:Ar ... [...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] |
Europium
Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanthanide, as it can be dented with a fingernail and easily cut with a knife. When oxidation is removed a shiny-white metal is visible. Europium was isolated in 1901 and is named after the continent of Europe. Being a typical member of the lanthanide series, europium usually assumes the oxidation state +3, but the oxidation state +2 is also common. All europium compounds with oxidation state +2 are slightly reducing. Europium has no significant biological role and is relatively non-toxic as compared to other heavy metals. Most applications of europium exploit the phosphorescence of europium compounds. Europium is one of the rarest of the rare-earth elements on Earth.Stwertka, Albert. ''A Guide to the Elements'', Oxford University Press, 1996, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenotime
Xenotime is a rare-earth phosphate mineral, the major component of which is yttrium orthophosphate ( Y P O4). It forms a solid solution series with chernovite-(Y) ( Y As O4) and therefore may contain trace impurities of arsenic, as well as silicon dioxide and calcium. The rare-earth elements dysprosium, erbium, terbium and ytterbium, as well as metal elements such as thorium and uranium (all replacing yttrium) are the expressive secondary components of xenotime. Due to uranium and thorium impurities, some xenotime specimens may be weakly to strongly radioactive. Lithiophyllite, monazite and purpurite are sometimes grouped with xenotime in the informal "anhydrous phosphates" group. Xenotime is used chiefly as a source of yttrium and heavy lanthanide metals (dysprosium, ytterbium, erbium and gadolinium). Occasionally, gemstones are also cut from the finest xenotime crystals. Etymology The name ''xenotime'' is from the Greek words κενός ''vain'' and τιμή '' ... [...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] |
Europium(III) Chloride
Europium(III) chloride is an inorganic compound with the formula EuCl3. The anhydrous compound is a yellow solid. Being hygroscopic it rapidly absorbs water to form a white crystalline hexahydrate, EuCl3·6H2O, which is colourless. The compound is used in research. Preparation Treating Eu2O3 with aqueous HCl produces hydrated europium chloride (EuCl3·6H2O). This salt cannot be rendered anhydrous by heating. Instead one obtains an oxychloride. Anhydrous EuCl3 is often prepared by the " ammonium chloride route," starting from either Eu2O3 or hydrated europium chloride (EuCl3·6H2O) by heating carefully to 230 °C. These methods produce (NH4)2 uCl5 :10 NH4Cl + Eu2O3 → 2 (NH4)2 uCl5 + 6 NH3 + 3 H2O :EuCl3·6H2O + ''2'' NH4Cl → (NH4)2 uCl5+ 6 H2O The pentachloride decomposes thermally according to the following equation: : (NH4)2 uCl5 → 2 NH4Cl + EuCl3 The thermolysis reaction proceeds via the intermediary of (NH4) u2Cl7 Reactions Europium(III) chloride is ... [...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] |
Europium(III) Oxide
Europium(III) oxide (Eu2O3), is a chemical compound of europium and oxygen. It is widely used as a red or blue phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors. It is also an agent for the manufacture of fluorescent glass. Europium fluorescence is used in the anti-counterfeiting phosphors in Euro banknotes. Europium oxide has two common structures: Monoclinic ( mS30, space group ''C''2/''m'', No. 12) and cubic ( cI80, space group ''I''a, No. 206). The cubic structure is similar to that of manganese(III) oxide. It may be formed by ignition of europium Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanth ... metal. It can react with acids to form the corresponding europium(III) salts. Gallery File:Tl2O3structure.jpg, Cubic Eu2O3 File:Gd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic Pentoxide
Arsenic pentoxide is the inorganic compound with the formula As2O5. This glassy, white, deliquescent solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is arsenic(III) oxide (As2O3). All inorganic arsenic compounds are highly toxic and thus find only limited commercial applications. Structure The structure consists of tetrahedral and octahedral centers linked by sharing corners. The structure differs from that of the corresponding phosphorus(V) oxide; as a result, although there is still a solid solution with that oxide, it only progresses to the equimolar point, at which point phosphorus has substituted for arsenic in all of its tetrahedral sites. Likewise, arsenic pentoxide can also dissolve up to an equimolar amount of antimony pentoxide, as antimony substitutes for arsenic only in its octahedral sites. Synthesis Historical Paracelsus Macquer found a crystallizable salt which he ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europium(III) Compounds
Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanthanide, as it can be dented with a fingernail and easily cut with a knife. When oxidation is removed a shiny-white metal is visible. Europium was isolated in 1901 and is named after the continent of Europe. Being a typical member of the lanthanide series, europium usually assumes the oxidation state +3, but the oxidation state +2 is also common. All europium compounds with oxidation state +2 are slightly reducing. Europium has no significant biological role and is relatively non-toxic as compared to other heavy metals. Most applications of europium exploit the phosphorescence of europium compounds. Europium is one of the rarest of the rare-earth elements on Earth.Stwertka, Albert. ''A Guide to the Elements'', Oxford University Press, 1996, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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