Lithium chloride, hydration

Lithium Chloride. Of the metal haUdes, calcium bromide [7789-41-5] CaBr2, ziac chloride [7646-85-7] ZnCl2, CaCl2, and lithium chloride [7447-41-8] LiCl, (Class 1, nonregenerative) are the most effective for water removal (4). AH are available ia the form of dehquescent crystals. The hydrates of LiCl are LiCl-nH2 O, where n = 1, 2, or 3. Lithium chloride solutions are more stable ia air and less corrosive than the other metal haUdes. The high solubihty of lithium carbonate [554-13-2] Li2C02, usually eliminates scale formation problems (see LiTHlUM COMPOUNDS). 

Catalyst A mixture of 5.26 g of rhodium chloride trihydrate, 0.34 g of palladium chloride, 18 g of carbon (Darco G-60), and 200 ml of water is rapidly stirred and heated to 80°. A solution of lithium hydroxide hydrate (2.7 g) in 10 ml of water is added in one portion and the heating discontinued. Stirring is continued overnight, after which the mixture is filtered and washed with 100 ml of 0.5 % aqueous acetic acid. The product is dried in a vacuum oven at 65°. About 20 g of the catalyst is thus obtained. 

Reactive ionic compounds are therefore useless to derive hydration enthalpies (or more generally, solvation enthalpies). Fortunately, there are many alternatives. Take lithium chloride, for example, and data from the NBS Tables [ 17]. The enthalpy of solution of this solid in water, at infinite dilution, is given by... 

C. Ende have shown that lithium chloride has a tendency to polymerize when dissolved in alcohol and other organic solvents H. C. Jones and co-workers have also shown that there is a tendency to form complexes between the lithium salt and the organic solvent while E. W. Washburn and E. W. Mclnnes calculate that in a JN-aq. soln. of lithium chloride, each mol. of the solute is hydrated with 18 mols. of the solvent. F. G. Donnan and W. E. Garner have studied the distribution ratio of lithium chloride between amyl alcohol and water. [LiCl]Am h[LiCl]Aq =0-0273. 

Several hydrates of lithium chloride have been reported. The existence of a monohydrated sodium chloride, NaCl.H20, is doubtful. E. Bevan 71 claimed to... 

Lithium Arsenates.—Lithium Orthoarsenate is obtained as the hemihydrate, 2Li3As04.H30, by the action of lithium carbonate on arsenic acid and allowing the solution to crystallise.4 The anhydrous salt is prepared by recrystallising this hydrate from fused lithium chloride 5 rhombic crystals of density 3-07 at 15° C. are obtained. These are soluble in dilute acetic acid they are extremely stable and may be heated to a white heat without fusion. With excess of arsenic acid the normal salt yields deliquescent rhombic prisms of lithium dihydrogen arsenate, 2LiH2As04.3H20, which with water revert to the normal salt.6... 

Properly used, a saturated salt sensor is accurate to 1 C between dew point temperatures of -12 and +38°C. Outside Ihtfse limits, small errors may occur ns a result of the multiple hydration characteristics of lithium chloride, which may produc d ambiguous results at 4I C. 12 C. 

In 1956 Owe Berg (115) advocated the existence in water of hydrates involving as many as 60 molecules per sodium chloride. He correctly noted that 60 water molecules could not be bound directly to one NaCl molecule (quite apart from the fact that there are no sodium chloride molecules in the solution) and that the hydrates, therefore, are to be regarded as compositions of structural transformations. Horne and Birkett (81) have also suggested the existence of large numbers of hydration. Thus, estimates of 45-50 water molecules were obtained by different independent methods for lithium ion hydration. 

Lanthanum nitrate, analysis of anhydrous, 5 41 Lead (IV) acetate, 1 47 Lead(II) 0,0 -diethyl dithiophos-phate, 6 142 Lead (IV) oxide, 1 45 Lead(II) thiocyanate, 1 85 Lithium amide, 2 135 Lithium carbonate, formation of, from lithium hydroperoxide 1-hydrate, 5 3 purification of, 1 1 Lithium chloride, anhydrous, 6 154 Lithium hydroperoxide 1-hydrate, 5 1... 

Lithium chloride, LiCl.—The anhydrous salt is obtained by evaporating to dryness in a current of hydrogen chloride or in presence of ammonium chloride the solution formed by dissolving the carbonate in hydrochloric acid, or decomposing the sulphate with barium chloride.4 Bogorodsky 5 has isolated three hydrates at very low temperatures the trihydrate, LiCl,3H20, is deposited in small needles at —15° C. the dihydrate, LiCl,2H20, crystallizes in cubes and at 12-5° C. octa-hedra of the monohydrate, LiCl,H20, are formed. At about 98° C. the anhydrous salt separates. 

Lithium nitrite, LiN02.—The monohydrate, LiN02,H20, is obtained by the interaction of lithium chloride and silver nitrite,7 and also by that of lithium sulphate and barium nitrite.8 It forms colourless, deliquescent needles, very soluble in water. At 0° C. its density is 1 615,9 and between 21° C. and 31° C. 1 671. Its molecular volume is 63-44.10 Under the influence of sunlight it decomposes, with formation of the red nitride. Oswald11 also prepared a colourless, deliquescent semihydrate, and proved that the colourless anhydrous salt becomes hydrated through the action of the moisture of the atmosphere. 

Alkylation of pseudoephedrine sarcosinamide can be used to prepare enantiomerically enriched A -methyl-a-amino acids. Anhydrous pseudoephedrine sarcosinamide has been prepared by the addition of sarcosine methyl ester to a mixture of pseudoephedrine, lithium chloride, and lithium methoxide. In contrast to the preparation of pseudoephedrine glycinamide, the amount of dipeptide by-product produced in the reaction is minimal, perhaps due to the increased steric hindrance of the N-methyl group of sarcosine. Thus, pure anhydrous pseudoephedrine sarcosinamide can be obtained from the crude acylation reaction mixture by precipitation from toluene and subsequent drying. Like anhydrous pseudoephedrine glycinamide, anhydrous pseudoephedrine sarcosinamide can be handled in the atmosphere for brief periods without consequence, but should be stored with scrupulous avoidance of moisture to prevent hydration. 

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