Rubidium metal

Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali group and is the second most electropositive and alkaline element. It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere. 

Rubidium metal alloys with the other alkaU metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double haUde salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and 2iac. These complexes are generally water iasoluble and not hygroscopic. The soluble mbidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide. 

Althoughmbidium is more electropositive than either calcium or magnesium, the equUibrium is driven to the right because the mbidium is continuously distiUed away from the reaction mixture. Rubidium metal can be purified by vacuum distiUation. 

Rubidium metal is commeicially available in essentially two grades, 99 + % and 99.9 + %. The main impurities ate other alkali metals. Rubidium compounds are available in a variety of grades from 99% to 99.99 + %. Manufacturers and suppliers of mbidium metal and mbidium compounds usually supply a complete certificate of analysis upon request. Analyses of metal impurities in mbidium compounds are determined by atomic absorption or inductive coupled plasma spectroscopy (icp). Other metallic impurities, such as sodium and potassium, are determined by atomic absorption or emission spectrograph. For analysis, mbidium metal is converted to a compound such as mbidium chloride. 

Rubidium hydroxide, 27 821-822 Rubidium iodide, 27 823 Rubidium metal alloys, 27 816 Rubidium metal, pure, 27 818 Rubidium oxides, 27 816, 823 Rubidium ozonide, 78 417 Rubidium silicates, 22 452 Rubidium sulfate, 27 821 Rubidium superoxide, 78 417 Rubidium tetrahydroborate physical properties of, 4 194t Ruby, 2 405 color, 7 329 Ruby glass, 7 344... 

Rubidium is located between potassium and cesium in the first group in the periodic table. It is the second most electropositive alkali element and reacts vigorously and explosively in air or water. If placed on concrete on a sunny day, it would melt and then react violendy with moist air to release hydrogen with enough heat to burn the hydrogen. If a chunk of rubidium metal is left on a table exposed to the air, it combusts spontaneously. Rubidium must be stored in oil, such as kerosene. 

Rubidium chloride is used for the production of rubidium metal, which, in the liquid form, has a high heat transfer coefflcient, making it useful as a coolant (along with other alkali metals) for nuclear reactors. 

Rubidium chlorides (RbCl) is a source of rubidium metal and is used as a chemical reagent. 

Cesium reacts with water in ways similar to potassium and rubidium metals. In addition to hydrogen, it forms what is known as superoxides, which are identified with the general formula CsO When these superoxides react with carbon dioxide, they release oxygen gas, which makes this reaction useful for self-contained breathing devices used by firemen and others exposed to toxic environments. 

Rubidium metal and its salts bave very few commercial apphcations. They are used in research involving magnetohydrodynamics and thermoionic experiments. Rubidium is used in pbotocells. The metal also is a getter of oxygen in vacuum tubes. The beta-emitter rubidium -87 is used to determine age of some rocks and minerals. Radioisotopes of rubidium have been used as radioactive tracers to trace the flow of blood in the body. The iodide salt treats goiters. Rubidium salts are in pharmaceuticals as soporifics, sedatives, and for treating epilepsy. 

Rubidium metal may be obtained from its carbonate, hydroxide or chloride by reduction with magnesium or calcium at high temperatures in the presence of hydrogen ... 

Rubidium chloride is used in preparing rubidium metal and many rubidium salts. Also, it is used in pharmaceuticals as an antidepressant and as a density-gradient medium for centrifugal separation of viruses, DNA, and large particles. Other applications are as an additive to gasoline to improve its octane number and as a catalyst. 

Rubidium hydroxide may be obtained as an intermediate in recovering rubidium metal from mineral lepidohte (see Rubidium). In the laboratory it may be prepared by adding barium hydroxide to a solution of rubidium sulfate. The insoluble barium sulfate is separated by filtration ... 

Pure rubidium metal is obtained by reducing pollucite or lepidolite ore using an active metal, followed by vacuum distillation (17). Another method is to reduce pure rubidium compounds thermochemically according to the following reactions (18) ... 

The supply and demand for rubidium compounds has grown steadily since the 1970s. In 1979 the U.S. demand was ca 1040 kg of contained rubidium (16), and total world demand was estimated at approximately twice that of the United States. Reserves of rubidium in North America are estimated at 2 x 103 kg the United States is 100% import-reliant for rubidium, and Canada is the principal source of the raw material (16). The demand for rubidium metal is small compared to the demand for rubidium compounds. Table 2 lists approximate prices of rubidium metal and rubidium compounds. Primary producers of rubidium are Cabot Performance Chemicals (Boyerstown, Pennsylvania), MSA Research Corporation (Callery, Pennsylvania), and CM Chemical Products, Inc. (Berkeley Heights, New Jersey). Research quantities of rubidium in standard and specialized ampuls are available from Strem Chemicals, Inc. (Newburyport, Massachusetts). 

Rubidium occurs in lepidolite (lithium aluminosilicate, in amount up to 1% Rb). in certain mineral waters and rare minerals. Rubidium salts may be recovered from the mother liquor upon crystallization of (1) lithium salts, (2) potassium salts. Rubidium metal is obtained by electrolysis of the fused chloride out of contact with air. 

Fullerene, black and shiny like graphite, is the subject of active current research because of its interesting electronic properties. When allowed to react with rubidium metal, a superconducting material called rubidium fulleride, Rb3C6o, is formed. (We ll discuss superconductors in more detail in Section 21.6.) Carbon nanotubes are being studied for use as fibers in the structural composites used to make golf clubs, bicycle frames, boats, and airplanes. On a mass basis, nanotubes are up to ten times as strong as steel. 

Rhenium pentachloride, 180 Rhenium sulfide, 177 Rhenium trichloride, 182 Rubidium, metallic, 79... 

The most popular thermionic detector (TID) is the nitrogen-phosphorus detector (NPD). The NPD is specific for compounds containing nitrogen or phosphorus. The detector uses a thermionic emission source in the form of a bead or cylinder composed of a ceramic material impregnated with an alkyl-metal. The sample impinges on the electrically heated and now molten potassium and rubidium metal salts of the active element. Samples which contain N or P are ionized and the resulting current measured. In this mode, the detector is usually operated at 600-800°C with hydrogen flows about 10 times less than those used for flame-ionization detection (FID). 

Norden, A., and A. Lodding Self-Transport, Electro Convection and Effective Self-Diffusion in Liquid Rubidium Metal. Z. Naturforsch. 22 a, 215 (1967). 

It takes 208.4 kj of energy to remove one mol of electrons from the atoms on the surface of rubidium metal. If rubidium metal is irradiated with 254-nm light, what is the maximum kinetic energy the released electrons can have ... 

Rubidium metal is a dangerous element to work with because it is so active chemically. However, no health hazards have been associated with any rubidium compounds. 

Use Analysis (testing for perchloric acid), source of rubidium metal. 

In 1861, shortly after their announcement of the discovery of cesium, Bunsen and Kirchhoff announced the discovery of rubidium in the mineral lepidolite. Rubidiums presence was indicated by two previously unknown deep red lines in the mineral s spectrum. The name rubidium comes from the Latin word rubidus, which refers to red of the deepest color. Bunsen succeeded in isolating rubidium metal itself. 

The demand for rubidium metal and its compounds is quite small. The metal is used as a getter to remove oxygen in vacuum tubes. The crystalline compound RbAg j has a conductivity similar to dilute sulfuric acid, which may make it useful in batteries and other electrochemical applications. Rubidium carbonate, Rb2C03, is used in the manufacture of specialized glasses. SEE ALSO Alkali Metals. 

EINECS 232-240-9 NSC 84273 Rubidium-chlorid Rubidium chloride Rubidium chloride (RbCI) Rubidium monochloride. Analysis (testing for perchloric acid), source of rubidium metal. Also used as a gasoline additive and as an antidepressant. Solid mp = 718° bp = 1390° d = 2.8000. Atomergic Chemetals Cabot Carbon Ltd. Cerac Noah Chem. 

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