Sulphate lithium

The Falin-Ciocalteu reagent (FCR) is a complex formed in a reaction between sodium tungstate and sodium molybdenate in hydrochloric add and phosphoric acid, which turns yellow after lithium sulphate is added. The reagent reads in an alkaline environment with reducing compounds. Such a reaction gives a blue chromophore which is observed by colorimetry. The Folin-Ciocalteu method is highly sensitive - both to phenolic and non-phenolic compounds, e.g. proteins, vitamin C, vitamin Bj, folic acid, Cu(I). The method is applied most frequently to determine the total content of phenolic compounds [34,35]. If that is the case, a sample for determination should be prepared in a proper manner to minimise the effect of non-phenolic... 

In 1818, A. Arfvedson 17 causticized lithium carbonate by means of calcium hydroxide, but the sparing solubility of lithium carbonate causes but a poor yield. L. Troost made the hydroxide by dissolving in water the oxide obtained by the combustion of the metal and C. G. Gmelin decomposed lithium sulphate by an eq. soln. of barium hydroxide. In either case, the soln. should.be evaporated rapidly to dryness in a silver vessel, and then fused. 

The properties of the alkali sulphates.—Lithium sulphate can be prepared as the anhydrous and hydrated as monohydrated lithium sulphate, Li2S04.H20 and sodium sulphate as the anhydrous salt, as heptahydrated sodium sulphate, NaS04-7H20 and decahydrated sodium sulphate, Na2S04-10H20. Mono- and trihydrated sodium salts have been reported—the former by J. Thomsen,22 the latter by H. Rose—but L. G. de Goppet has questioned the two last-named hydrates. 

According to H. Kolbe,41 lithium sulphate is insoluble in absolute ethyl alcohol, but C. W. G. Kastner found it to be soluble in aq. alcohol, and F. A. H. Schreine-makers and W. A. van Dorp found lithium sulphate to be virtually insoluble in 80 per cent, alcohol, but the solubility increases rapidly as the amount of water increases. The solubility of sodium sulphate in aq. alcohol of different temp, and cone, has been studied by C. A. L. de Bruyn.42 Sodium sulphate is virtually insoluble in alcohol of greater cone, than about 72 per cent. For example, at 15°, with decahydrated sodium sulphate, per 100 grms. of soln. ... 

Aq. soln. of lithium sulphate furnish monoclinic plates of monohydrated lithium sulphate, LiS04.H20. G. C. A. van Dorp s equilibrium curves are shown in Fig. 44. If a cone. soln. of lithium sulphate be kept boiling for some time, J. W. Retgers 44 says that rhombic needle-like crystals of the anhydrous salt are... 

The YjiV-soln. of lithium sulphate is about two-thirds ionized. O OlA-soln. of potassium sulphate at 0° are 84 5 per cent, ionized OllV-soln., 65 5 per cent. andO 22V-soln., 59-5 per cent, ionized. G. N. Lewis and G. A. Linhart have measured the degree of ionization of soln. of potassium sulphate calculated from A. A. Noyes and G. K. Falk s determination of the ratio A/AM and the value calculated thermodynamically, and found the former to be about 20 per cent, less for soln. with 0 01 mol. per litre. The corresponding numbers at 18° are 83-0, 66 0, and 60-l per cent. 

E. F. Anthon found ammonium sulphate to be insoluble in absolute alcohol, while alcohol of sp. gr. 0 872 dissolves O 2 grm. of the salt, and in more dil. alcohol the salt is more soluble. J. J. Pohl obtained an analogous result. J. Traube and 0. Neuberg found that with mixtures of alcohol and water, the soln. separates into two layers with certain couc.—e.g. with alcohol with a sp. gr. over 0 9530 at 15°— in the lower aq. layer, the mol. ratio of the three components is approximately constant, indicating that a definite compound is probably formed. These soln. have been studied by G. Bodlander, F. A. H. Schreinemakers, and C. A. L. de Bruyn. This phenomenon, layer separation, has also been observed with lithium sulphate in alcohol-water soln. C. E. Linebarger found the solubility in aq. isopropyl alcohol at 20° to be 0 4, 2 0, and 6 7 grms. (N 114)2804 per 100 grms. of soln. in the presence of 70, 50, and 20 per cent, of CsH7OH. W. Erdmann found ammonium sulphate to be insoluble in acetone. 

According to the ionic hypothesis, if the solubility product [Li]2[C0"3] is not altered, the solubility can be increased by the union of one or other of the ions of the carbonate forming complexes with the added salt. This effect is not very marked with potassium or sodium chloride or nitrate. The marked increase in the solubility with sodium and potassium sulphates is due to the formation of lithium sulphate, but with the ammonium salts soluble complexes like Li(NH3) and NH2C00 may be formed just as is the case with magnesium carbonate in the presence of ammonium salts. 

Lithium Carbonate. Add a saturated sodium carbonate solution to 2-3 ml of a saturated lithium sulphate or chloride solution. What do you observe Write the equation of the reaction. Acquaint yourself with the solubility of the alkali metal carbonates in water. 

Preparation of Lithium Peroxide, a. Preparation o/ Lithium Hydroxide Monohydrate. Put 5 g of lithium sulphate into a 400-ml... 

Lithium sulphate (anhydrous) [10377-48-7] M 109.9. Crystd from H2O (4ml/g) by partial evaporation. 

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