Rubidium ammonia

Dicaesium acetylide Copper(ll) acetylide Dicopper(l) acetylide Silver acetylide Caesium acetylide Potassium acetylide Lithium acetylide Sodium acetylide Rubidium acetylide Lithium acetylide-ammonia Dipotassium acetylide Dilithium acetylide Disodium acetylide Dirubidium acetylide Strontium acetylide Silver trifluoromethylacetylide Sodium methoxyacetylide Sodium ethoxyacetylide... 

See Monolithium acetylide-ammonia Gases Monopotassium acetylide Non-metal oxides Rubidium acetylide Non-metal oxides Sodium acetylide Non-metal oxides... 

All hydroxides (except lithium, sodium, potassium, cesium, rubidium, and ammonia) are insoluble Ba(OH)2 is moderately soluble Ca(OH)2 and Sr(OH)2 are slightly soluble. 

The mixed alum solution, on treatment with ammonia or potassium carbonate, forms carbonates of potassium, rubidium and cesium. Rubidium carbonate is separated from other alkab metal carbonates by fractional crystal-bzation (see Rubidium)... 

Also, the salt may be prepared by adding ammonium carbonate to a solution of rubidium hydroxide. The solution is evaporated to dryness to expel ammonia. 

Alternatively, Rb sulfate may be obtained by treating a hot solution of rubidium aluminum sulfate (rubidium alum) with ammonia solution. Aluminum hydroxide precipitates. The product mixture is fdtered. The filtrate on evaporation crystaUizes rubidium sulfate. 

Dihydroxo-diaquo-diammino-chromic Chloride, [Cr(NH3), (H20)2(OH)2]Cl, is formed by the addition of ammonia or pyridine to an aqueous solution of tetraquo-diammino-chloride, or saturating an aqueous acetic acid solution with rubidium chloride. It forms light red violet crystals which are insoluble in water. The iodide is obtained from the bromide on addition of potassium iodide to a dilute acetic acid solution of the salt as a light red violet precipitate. The thiocyanate, [Cr(NH3)2(H20)2(OH)2]SCN, is amorphous, and is prepared from the bromide by dissolving in aqueous acetic acid and adding potassium thiocyanate. 

Similarly, the reaction of metallic rubidium with another metal in ammonia led to the appropriate heterobimetallic amides, as in the reaction of Rb with Ca in supercritical ammonia at 573 K yielding RbCa(NH2)3. " " which consists of one-dimensional infinite face-sharing anion-octahedra occupied by calcium and connected into a three-dimensional network by the rubidium ions (Rb N contacts between 3.11 and 3.92 A). 

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. 

The electro-affinity of lithium is smaller than that of any of the other alkali metals, and it exhibits a greater tendency than the other alkali metals to form complex salts—e.g. the solubility of ammonia in water is raised by the addition of a lithium salt, which presumably unites with the ammonia the solubility curves of the lithium salts in water usually show more breaks than the corresponding salts of the other alkali metals owing to the formation of hydrates. Potassium, rubidium, and caesium seem to have a smaller and smaller tendency to form complex salts as the at. wt. of the element increases otherwise expressed, the electro-affinity, or the ionization tendency of the alkali metals increases as the at. wt. increases. This is illustrated by the heats of ionization. According to W. Ostwald,27 the heat of ionization per gram-atom iB... 

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. 

V. 1 Olivier a trace of iodine. L. Dieulafait found traces of lithium, rubidium, and caesium salt H. Beckurts, chlorates and perchlorates up to 5 64 per cent. M. Marcker, borates and humus C. F. Schfinbein, nitrites and ammonia R. Wagner, iodine and bromine. H. Griineberg says the former is present as iodate or periodate. 

Rb2HP04, by the interaction of eq. quantities of rubidium hydroxide and ortho-phosphoric acid in cone, aqua ammonia. The resulting precipitate of ammonia rubidium phosphate loses all its combined ammonia in vacuo over sulphuric acid. E. von Berg prepared hydrated dicsesium hydrophosphate, Cs2HP04.H20, in a similar manner. 

The compounds MC=CCH3 (M = Na, K) were described earlier.1 The rubidium and cesium derivatives have now been obtained by the reaction of the metals with propyne in liquid ammonia, and their crystal structures studied by X-ray powder diffraction. The compounds are isostructural with those isolated previously, and the c/a ratio in the tetragonal unit cell decreases linearly with the increasing ionic radii of the alkali metals ions.120... 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

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