Rubidium phosphate

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. 

Rubidium phosphates.—The three phosphates are prepared by the interaction of phosphoric acid and rubidium hydroxide or carbonate in appropriate proportions.13 The primary phosphate, RbH2P04, is acidic in aqueous solution the other two are alkaline. When heated at 244° C. the primary phosphate loses water, yielding the acid pyrophosphate, RbaH2P207.14 The secondary phosphite forms a monohydrate,... 

More work is needed to describe the solubility of other rubidium phosphates. 

Zinc (76ppm of the earth s crust) is about as abundant as rubidium (78 ppm) and slightly more abundant than copper (68 ppm). Cadmium (0.16 ppm) is similar to antimony (0.2 ppm) it is twice as abundant as mercury (0.08 ppm), which is itself as abundant as silver (0.08 ppm) and close to selenium (0.05 ppm). These elements are chalcophiles (p. 648) and so, in the reducing atmosphere prevailing when the earth s crust solidified, they separated out in the sulfide phase, and their most important ores are therefore sulfides. Subsequently, as rocks were weathered, zinc was leached out to be precipitated as carbonate, silicate or phosphate. 

VIOLET Potassium compounds other than silicates, phosphates and borates rubidium and cesium are similar. Color is masked by lithium and/or sodium, appears purple-red through cobalt glass and bluish-green glass. 

The electrical conductivities of soln. of a great many compounds in liquid hydrogen halides have been measured by E. H. Archibald and D. McIntosh. The conductivity is raised considerably by phosphoryl chloride. Sodium sodium sulphide, borate, phosphate, nitrate, thiosulphate, and arsenate chromic anhydride potassium nitrate, hydroxide, chromate, sulphide, bisulphate, and ferro- and ferri- cyanide ammonium fluoride and carbonate j rubidium and caesium chloride magnesium sulphate calcium fluoride ... 

E. von Berg prepared colourless prismatic crystals of tetrahydrated trirubidium phosphate, Rb3P04.4H20, by crystallization, over sulphuric acid, of a soln. of two mols. of phosphoric acid, and three of rubidium carbonate, and he obtained crystals of pentahydrated tricsesium phosphate, Cs8PC>4.5H20, in a similar manner. 

A phosphorus-specific thermionic detector was also adapted from GLC (See Section III.3.b) for use with small-bore HPLC columns208,307,330,334. Based on an electrically heated rubidium salt bead, it permits detection limits of 0.2-0.5 ng of phosphorus and its response is linear with the amount of phosphorus over several orders of magnitude. This detector yields good results with phosphates which cannot be detected by UV spectrophotometry or by fluorescence measurements. 

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. 

Caesium phosphates.—In constitution and properties the phosphates resemble the corresponding salts of rubidium. They are prepared by analogous methods.4... 

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