The separation of caesium from the minerals which contain it is an exceedingly difficult and laborious process.
Caesium compounds can be readily recognized by the two bright.
They are silicates, usually orthosilicates, of aluminium together with alkalis (potassium, sodium, lithium, rarely rubidium and caesium), basic hydrogen, and, in some species magnesium, ferrous and ferric iron, rarely chromium, manganese and barium.
It combines with alkaline chlorides - potassium, rubidium and caesium - to form crystalline plumbichlorides; it also forms a crystalline compound with quinoline.
is the sign of an alkali metal (potassium, sodium, rubidium, caesium), silver or ammonium, and M 111 denotes one of the trivalent metals, aluminium, chromium or ferric iron.
The solubility of the various alums in water varies greatly, sodium alum being readily soluble in water, whilst caesium and rubidium alums are only sparingly soluble.
Titanium sesquisulphate, T12(S04)3.8H20, obtained by concentrating the violet solution formed when the metal is dissolved in sulphuric acid, is interesting since it forms a caesium alum, CsTi(S04)2.12H20.
In modern chemistry alkali is a general term used for compounds which have the property of neutralizing acids, and is applied more particularly to the highly soluble hydrates of sodium and potassium and of the three rarer "alkali metals," caesium, rubidium and lithium, also to aqueous ammonia.
Caesium is found in the mineral springs of Frankenhausen, Montecatini, di Val di Nievole, Tuscany, and Wheal Clifford near Redruth, Cornwall (W.
Bunsen, the best source of rubidium and caesium salts is the residue left after extraction of lithium salts from lepidolite.
This residue consists of sodium, potassium and lithium chlorides, with small quantities of caesium and rubidium chlorides.
The caesium and rubidium are separated from this by repeated fractional crystallization of their double platinum chlorides, which are much less soluble in water than those of the other alkali metals (R.
The platino-chlorides are reduced by hydrogen, and the caesium and rubidium chlorides extracted by water.
Zeit., 1892, 16, p. 335) separate rubidium and caesium from the other alkali metals by converting them into double chlorides with stannic chloride; whilst J.
In order to separate caesium from rubidium, use is made of the different solubilities of their various salts.
The double chloride of caesium and antimony 3CsC1 2SbC1 3 (R.
The metal has been obtained by electrolysis of a mixture of caesium and barium cyanides (C. Setterberg, Ann., 1882, 211, p. loo) and by heating the hydroxide with magnesium or aluminium (N.
Hackspill (Comptes Rendus, 5905, 141, p. 101) finds that metallic caesium can be obtained more readily by heating the chloride with metallic calcium.
The atomic weight of caesium has been determined by the analysis of its chloride and bromide.
Caesium hydroxide, Cs(OH) 2, obtained by the decomposition of the sulphate with baryta water,is a greyish-white deliquescent solid,which melts at a red heat and absorbs carbon dioxide rapidly.
CsCl, is obtained by the direct action of chlorine on caesium, or by solution of the hydroxide in hydrochloric acid.
Caesium sulphate, Cs 2 SO 4, may be prepared by dissolving the hydroxide or carbonate in sulphuric acid.
Caesium nitrate, CsNO 3, is obtained by dissolving the carbonate in nitric acid, and crystallizes in glittering prisms, which melt readily, and on heating evolve oxygen and leave a residue of caesium nitrite.
Matthiessen, sodium ranks fourth to silver, copper and gold as a conductor of electricity and heat, and according to Bunsen it is the most electropositive metal with the exception of caesium, rubidium and potassium.
lithium, sodium, potassium, rubidium and caesium, and of the alkaline earth metals, viz.
The chlorine is not completely precipitated by silver nitrate in nitric acid solution, the ionization apparently not proceeding to all the chlorine atoms. Thallic iodide, T11 3, is interesting on account of its isomorphism with rubidium and caesium tri-iodides, a resemblance which suggests the formula T11 (12) for the salt, in which the metal is obviously monovalent.
1898, 1 7, p. 355) has also obtained a manganese caesium alum.
The best source of rubidium salts is the residue left after extracting lithium salts from lepidolite, the method of separation being based on the different solubilities of the platino-chlorides of potassium, rubidium and caesium in water (R.
It closely resembles caesium and potassium in its general properties.
These sulphides are much less hygroscopic than the corresponding caesium compounds.
Within two years of the invention the authors announced the discovery of two metals, rubidium and caesium, closely allied to sodium, potassium and lithium in properties, in the mineral lepidolite and in the Diirkheim mineral water.
Rubidium, caesium, thallium, indium and gallium were first discovered by means of this instrument; the study of the rare earths is greatly facilitated, and the composition of the heavenly bodies alone determinable by it.
By taking appropriate differences the following facts will be observed: (1) the replacement of potassium by rubidium occasions an increase in the equivalent volumes by about eight units, and of rubidium by caesium by about eleven units; (2) replacement in the same order is attended by a general increase in the three topic parameters, a greater increase being met with in the replacement of rubidium by caesium; (3) the parameters x and, p are about equally increased, while the increase in w is always the greatest.
CAESIUM (symbol Cs, atomic weight 132.9), one of the alkali metals.
Many trihaloid salts of caesium are also known, such as CsBr 3, CsC1Br 2, Cs13, CsBrI 2, CsBr 2 I, &c. (H.
Tutton's investigations of the morphotropic effects of the metals potassium, rubidium and caesium, in combination with the acid radicals of sulphuric and selenic acids, showed that the replacement of potassium by rubidium, and this metal in turn by caesium,was accompanied by progressive changes in both physical and crystallographical properties, such that the rubidium salt was always intermediate between the salts of potassium and caesium (see table; the space unit is taken as a pseudo-hexagonal prism).
Ber., 1860), although caesium salts had undoubtedly been examined before, but had been mistaken for potassium salts (see C. F.
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