Uranate potassium

Uranyl Perchlorate, UOjlCIO lj.hHgO, is prepared by adding perchloric acid to a solution of potassium uranate, filtering off the precipitated potassium perchlorate, and evaporating the filtrate over phosphorus pentoxide. It forms yellow prismatic ciy stals, which melt at 90° C, and at 100° C. lose water, yielding the tetrahydrate, V0, C10,) AB. 0. 

Silver Diuranate, Ag2U2 7 separates as an orange-red precipitate w hen freshly precipitated silver oxide is added to a solution of uranyl nitrate. It is also formed by the action of potassium uranate on fused silver nitrate. 

Potassium Uranyl Carbonate, K4U02(C03)a, may be prepared by the action of carbon dioxide on potassium uranyl cyanide, or by evaporating at moderate temperature a solution containing potassium bicarbonate and potassium uranate. It crystallises in small hexagonal prisms, which are stable in dry air and dissolve in cold water without decomposition. The solution is hydrolysed on warming, and the addition of alkali causes j recipitation of uranyl hydroxide. 

Light orange when finely divided. Aqueous slurries show a distinctly alkaline reaction within a few minutes. Soluble in dilute hydrochloric acid and sulfuric acid, as well as in 2 N acetic acid (except for potassium uranate). 

Dickens PG, Powell AV (1991) Powder neutron diOractimt study of potassium uranate(V), KUO3. J Mater Chem 1 137-138... 

At the end of the eighteenth century, scientists thought that pitchblende was a mixture of iron and zinc compounds. In 1789 Martin Heinrich Klaproth (1743—1817) discovered a new metallic element in a sample of pitchblende, which he named uranus after the recently discovered planet. Although what he actually discovered was the compound uranous oxide (UOj), it was adequate to establish him as the discoverer of uranium. For almost a century, scientists believed that the compound uranous oxide (UO ) was the elemental metal uranium. In 1841 Eugene-Melchoir Pefigot (1811—1890) finally isolated the metal uranium from its compound. Even so, no one knew that both the compounds and metal of uranium were radioactive until 1896, when Henri Becquerel (1852—1908) mistakenly placed apiece of potassium... 

Di(uranate) Potassium, K2U207, mw 666.34, or K2U207.3H30 yel salt in sol in water. 

Uranous Salt. — The solution of 1 gm. of uranium nitrate in 20 cc. of water and 1 cc. of dilute sulphuric acid should be colored red on the addition of 0.1 to 0.2 cc. of decinormal potassium permanganate. 

Uranyl-vanadates.—By adding uranic anhydride to fused potassium or sodium metavanadate, microscopic, rectangular, fluorescent plates of the compositions K(U02)V04 and Na(U02)V04 are obtained. These are probably derivatives of a relatively stable uranyl-... 

An interesting case of selective oxidation in solution is given hy Jones,2 who has studied the absorption spectrum of a solution of uranous bromide in a mixture of water and methyl alcohol. Addition of potassium perchlorate effects an alteration in the absorption bands m such a manner as to show that the portion of the uranous salt combined with the methyl alcohol has undergone no change, whilst that united with the water has become oxidised. 

Ternary System Phase Diagram Determinations Concerning Potassium Electrolyte Influence on Aqueous Solutions of Dioxane or T etrahy drof uran... 

Ignites on contact with antimony, arsenic, boron, iodine, phosphorus, selenium. Ignites when warmed with bismuth, carbon, chromium, lead, sulfur. Incandescent reaction with aluminum, cadmium, cobalt, iron, molybdenum, nickel, potassium, sodium, thorium, titanium, tungsten, uran-... 

Double fluorides have been obtained by reduction of complex alkali uran d fluoride solutions by means of oxalic or formic acid under the influence of sunlight. The potassium salt, KUFj, is a green powder, insoluble in water. 

Uranous oxide is also obtained in the form of black microscopic crystals when urano-uranic oxide is reduced uith carbon or heated with a little hydrofluoric acid when crystallised uranic hydroxide is heated in hydrogen when uranyl chloride is heated with potassium in a current of hydrogen, or with a mixture of ammonium and sodium... 

Colloidal Uranous Oxide.—During the electrolysis of a solution of uranyl chloride a black reduction product is precipitated at the cathode. This precipitate dissolves in water, forming a dark-coloured colloidal solution, which by titration with potassium permanganate, before and after reduction with zinc, has been shown to contain uranous oxide. A similar solution may be obtained by the reduction of uranyl chloride by zinc or copper in dilute acid solution. When very dilute, the solution has a yellow tinge. In an electric field it becomes decolorised at the anode and precipitation takes place at the cathode. It behaves as a typical positive colloid with coagulating agents. 

According to Aloy, a black crystalline hydrate, of composition UO2.2H2O, is obtained when crystallised uranous sulphate is treated with hot potassium or sodium hydroxide solution. The product, when thoroughly w ashed, remains stable in air for several days. It dissolves in dilute acids, yielding uranous salts. On heating, it is completely converted to the green oxide. 

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