Rubidium chloride, reaction

Preparation. It is made by the reaction of metallic sodium with hot molten rubidium chloride. 

Rubidium chloride even slows the reaction, this is especially well seen within a time span of 1-3 hr after the start of the process (Fig. 2, curve 2). In this case the normal salt effect is likely to prevail over the effect of oximate ion pair separation due to substitution of the potassium cation by the rubidium cation. The addition of cesium carbonate during the first 1.5 hr does not much affect the rate of the formation of 2-phenylpyrrole. The accelerating effect of these additives becomes evident only 2 hr after the beginning of the reaction and gradually increases (5 hr later the yield gain of pyrrole is 7% as compared with a standard run, Fig. 2, curve 4) which seems to result from a slow rate of heterophase exchange process ... 

The reaction was carried out in dioxane, HMPA, and sulfolane as well as in mixtures of dioxane-DMSO (5 1 by volume) and water-DMSO (1 2) at 100-140°C with alkali metal (Li, Na, K, Rb, Cs) hydroxides, tetrabu-tylammonium hydroxide, and rubidium chloride examined as catalysts. All tests were run in an autoclave (1 L) at an initial acetylenic pressure of 12 atm. The most significant effect on the yield of 1-ethynylcyclo-hexanol (110) is that of the catalyst and the solvent. According to their diminishing efficiency, the catalysts examined are arranged as follows KOH RbOH > (Bu4)NOH > LiOH RbCl failed to catalyze the reaction and in the presence of CsOH, resinification was observed. The alcohol 110 is formed most readily in aqueous DMSO, dioxane being next in efficiency (with account for the yield based on the oxime consumed). Addition of DMSO to dioxane does not improve the yield of 110, and only trace amounts of this compound were obtained in HMPA and sulfolane. 

Tracers were not limited however to catalyst sulfur catalysed sulfur exchange reactions were studied too. An early study of sulfur exchange was also preformed in the liquid phase at 273 K, catalysed by chlorides, namely RbCl and AICI3.A much higher activity of rubidium chloride in comparison with that of AICI3, has been reported. 

Rubidium was first discovered by Robert Bunsen and Gustav Kirchhoff in 1861(this is the same Bunsen of the Bunsen burner that you can find in nearly every chemistry classroom). He was able to identify rubidium because of its unique spectral characteristics. The metal was first produced by the reaction of rubidium chloride (RbCl) with potassium. 

Precipitate with aq. ammonia. Evaporate the soln. down to about 100 c.c., and filter the ot liquid so as to remove calcium sulphate. The cone. soln. is sat. with ammonium alum and allowed to stand for some time. The mixed crystals of potassium, rubidium, and oeesium alums and of lithium salt are dissolved in 100 c.c. of distilled water and recrystal-lized. The recrystallization is repeated until the crystals show no spectroscopic reaction for potassium or lithium. The yield naturally depends on the variety of lepidolite employed. 100. grms of an average sample gives about 10 grms. of crude crystals and about 3 grms. of the purified caesium and rubidium alums. For the purification of caesium and rubidium salts, see the chlorides. The mother-liquors are treated with an excess of barium carbonate, boiled, and filtered. The filtrate is acidified with hydrochloric acid, and evaporated to dryness. The residue is extracted with absolute alcohol in which lithium chloride is soluble, and the other alkali chlorides are sparingly soluble. 

An intimate mixture ot 274 grms. of rubidium iron alum, or 260 grms. of rubidium aluminium alum with 100 grms. of calcium carbonate, and 27 grms. of ammonium chloride, is heated in a nickel crucible to a dull red heat until ammonia vapours are no longer evolved, and then the temp, is raised to redness. The product is ground with a litre of cold water for 15 minutes filtered by suction and washed with 400 c.c. of water, added in small portions at a time. The combined sulphuric acid is precipitated by the addition of barium hydroxide, and the filtered liquid boiled while a stream of carbon dioxide is passed through the soln. If the soln. loses its alkaline reaction, and yet retains some calcium, a little rubidium carbonate must be added to precipitate calcium carbonate. The soln. is then treated with hydrochloric acid and evaporated. 

SAFETY PROFILE A highly corrosive irritant to the eyes, skin, and mucous membranes. Mildly toxic by inhalation, Explosive reaction with alcohols + hydrogen cyanide, potassium permanganate, sodium (with aqueous HCl), tetraselenium tetranitride. Ignition on contact with aluminum-titanium alloys (with HCl vapor), fluorine, hexa-lithium disilicide, metal acetylides or carbides (e.g., cesium acetylide, rubidium ace-tylide). Violent reaction with 1,1-difluoro-ethylene. Vigorous reaction with aluminum, chlorine + dinitroanilines (evolves gas). Potentially dangerous reaction with sulfuric acid releases HCl gas. Adsorption of the acid onto silicon dioxide is exothermic. See also HYDROGEN CHLORIDE (AEROSOL) and HYDROCHLORIC ACID. 

The wet oxide reacts explosively with molten aluminum-magnesium aUoys. Violent reaction when heated with powdered aluminum, calcium disilicide, magnesium, metal acetyKdes (e.g., calcium acetyKde + iron(III) chloride (on ignition), cesium acetyKde (incandescent reaction when warmed), rubidium acetyKde). Reacts violently with Al, Ca(OCl)2, N2H4, ethylene oxide. See also IRON and IRON COMPOUNDS. 

Schlenk and Marcus in 1914 found that triphenylmethyl chloride reacted with sodium amalgam in dry ether solution, when the operation was carried out in an atmosphere of nitrogen. The resulting compound, sodium triphenylmethyl, was a brick-red mass, decomposed by moisture or carbon dioxide. Kraus and Kawamura in 1928 showed that triphenylmethyl chloride reacts with sodium and potassium in liquid ammonia, but that the potassium compound is more stable than the sodium derivative. A number of compounds similar in structure to triphenylmethyl have since been sho wn to give similar reactions. Rubidium and esesium also form similar derivatives. ... 

Detection and Estimation. — Indium salts produce a blue-violet color in the flame, in which two brilliant blue lines are visible, 4511.5 and X 4102. Very small amounts of indium may be detected by microchcmical methods, using rubidium indium chloride. Other reactions are —... 

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