Barium iodide sulphate

Chloro - aquo - tetrammino - chromic Iodide, [Cr(NH3)4 (H20)C1]I2, is best prepared by decomposition of the sulphate with excess of barium iodide it is easily soluble in water and crystallises in red prisms. 

The iodide, [Pt(NH3)4(OH)2]I2, is produced by the action of barium iodide on the sulphate, and crystallises in small hexagonal prisms. 

Ethyl perchlorate, C2H5OCIO3, was first prepared by Hare and Boyle [2] as early as 1841. These authors drew attention to the highly explosive character of the substance and the danger of handling it. It is an oil liable to explode even when it is poured from one vessel into another. They obtained it by digesting barium ethyl sulphate with barium perchlorate. Later it was prepared by Roscoe [3] by acting with silver perchlorate on ethyl iodide. 

The natural history of chemistry consists since many centuries in empirical rules about the relative affinity of various elements. Though metathetical reactions are frequently used in preparation, the main origin is the filtering of insoluble precipitates, as when an aqueous solution of silver sulphate and another of barium iodide leave almost pure water in the filtrate ... 

Caesium iodide, Csl.—The iodide is prepared by the action of caesium sulphate on barium iodide. It forms crystals, melting at 621 0° C.,15 and boiling at 1280° C.,16 the vapour-pressure in atmospheres corresponding with the expression17... 

Thallium diethyl iodide cr stallises from water in white plates when quite pure, and investigators differ regarding its temperature of decomposition. It may he prepared from the corresponding chloride or bromide by the addition of potassium iodide to their aqueous solutions, or by the interaction of thallium diethyl sulphate and barium iodide, also by use of the Grignard reagent. It is difficultly soluble in water, alcohol, or ammonia, but may easily be reerystaliised from pyridine. 

The adsorption of salts having an ion in common with the precipitate roughly follows the Paneth-Fajans-Hahn adsorption rule which postulates that the less soluble the salt, the more easily is it incorporated into a precipitate. For example barium chloride is more readily adsorbed by barium sulphate than is barium iodide, which is much more soluble than the chloride. 

The exceptional character o fluorine.—Fluorine has a little more individuality, so to speak, than the other three members of the family (1) There are no compounds of oxygen and fluorine (2) Chlorine, bromine, and iodine or the haloid acids show no signs of the remarkable effect of hydrofluoric acid and of fluorine on silicon (3) The solubilities of the sulphates, nitrates, and chlorides of barium, strontium, calcium, and magnesium decrease with increasing at. wt. of the metal, while the solubilities of the hydroxides increase the solubilities of the iodides, bromides, and chlorides... 

The detection and determination ot the perchlorates.—The perchlorates give no precipitates with silver nitrate or barium chloride soln. cone. soln. give a white crystalline precipitate with potassium chloride. Unlike all the other oxy-acids of chlorine, a soln. of indigo is not decolorized by perchloric acid, even after the addition of hydrochloric acid and they do not give the explosive chlorine dioxide when warmed with sulphuric acid unlike the chlorates, the perchlorates are not reduced by the copper-zinc couple, or sulphur dioxide. Perchloric acid can be titrated with —iV-alkali, using phenolphthalein as indicator. The perchlorates can be converted into chlorides by heat and the chlorides determined volumetrically or gravimetrically they can be reduced to chloride by titanous sulphate 28 and titration of the excess of titanous sulphate with standard permanganate they can be fused with zinc chloride and the amount of chlorine liberated can be measured in terms of the iodine set free from a soln. of potassium iodide and they can be... 

G. Taddei7 prepared potassium iodide by adding a dil. soln. of potassium monosulphide to an alcoholic soln. of iodine. In place pf potassium sulphide, J. von Liebig and C. Wittstock used barium sulphide, prepared by calcining sulphate with coke. According to R. Schindler, the products obtained by the sulphide process are contaminated with sulphur compounds. G. S. Serullas treated potassium antimoniate (prepared by calcining tartar emetic) with an alcoholic soln. of iodine as long as the soln. was decolorized. The filtered soln. was evaporated to the point of crystallization. 

Potassium iodide can also be obtained from the aq. extract of kelp or from the mother liquid remaining after the separation of sodium chloride and potassium sulphate from sea-water by evaporation. In E. Allary and J. Pellieux process,8 the liquid is evaporated to dryness and roasted in a special furnace so as to avoid a loss of iodine. The product is fractionally extracted with cold water, when a soln. is obtained which on evaporation gives a residue with 50 per cent, of alkali iodide. This product is extracted.in a special digester with 50 per cent, alcohol. The solvent dissolves little more than the iodides. The alcohol is distilled off, and on evaporation a residue containing about 34 per cent, of potassium iodide, and 66 per cent, of sodium iodide is obtained. To convert the latter into potassium iodide, the proper quantity of a soln. of potassium carbonate is added and carbon dioxide passed into the liquid whereby sodium bicarbonate is precipitated. The precipitate is separated by a filter press, and the small amount of sodium bicarbonate remaining in the soln. is separated by the addition of a little hydrochloric acid and the sodium chloride and potassium iodide separated by fractional crystallization. In E. Sonstadt s process, the mother liquid is treated with chlorine mixed with potassium chlorate or permanganate so as to convert the iodine into iodate. A soln. of a barium salt is added, and the barium iodate treated with potassium sulphate. Barium sulphate is precipitated, and the soln. of potassium iodate is evaporated to dryness and calcined to convert the iodate to iodide. The latter is purified by crystallization. 

Sulphurous Acid.—200 c.c. of the beer, acidified with 5 c.c. of syrupy phosphoric acid, are distilled in a current of carbon dioxide, about 100 c.c. of distillate being collected in 50 c.c. of iodine solution (5 grams of iodine and 7-5 grams of potassium iodide per litre). The iodine solution is afterwards acidified with hydrochloric acid and boiled to expel the excess of iodine, the sulphuric acid formed being then precipitated by means of barium chloride. The presence of more than traces of sulphates indicates the addition of sulphite or sulphurous acid to the beer in such case, the barium sulphate is collected and weighed as usual BaSO X 1-372 = weight of SO per litre of the beer. 

H. M. Dawson and J. McCrae, D. P. Konowaloff, and W. Gaus also used soln. of various salts of the alkali metals, and of potassium, sodium, cupric, or barium hydroxide in place of water and also copper sulphate, copper chloride, zinc sulphate, and cadmium iodide while M. 8. Sherrill and D. E. Russ examined the effect of ammonium chromate. W. Herz and A. Kurzer examined the distribution of ammonia between water and a mixture of amyl alcohol and chloroform. Observations on the distribution of ammonia between water and chloroform were made by T. S. Moore and T. F. Winmill, G. A. Abbott and W. C. Bray, and J. M. Bell. J. H. Hildebrand gave for the molar fraction N X104 of ammonia at 1 atm. press., and 25°, dissolved by ethyl alcohol, 2300 methyl alcohol, 2730 and water, 3300. 

Anhydrous hydrazine dssolves many salts, thus, 100 parts of solvent at 12-5°-13° dissolve 12-2 parts of sodium chloride 8 5, of potassium chloride 56-4, of potassium bromide 135-7, of potassium iodide 26-6, of sodium nitrate 21-7, of potassium nitrate and 814, of barium nitrate. The hydrazine seemed to unite with sodium chloride with a warm soln. of ammonium chloride, ammonia is evolved, and in the cold, there seems to be a state of equilibrium a complex salt seems to be formed with lead nitrate. An aq. soln. of hydrazine hydrate also dissolves a number of salts, potassium bromide and iodide, ammonium sulphate, potassium cyanide, barium nitrate, magnesium sulphate, etc. According to T. W. B. Welsh and H. J. Broderson, the solubility of the metal haloids seems to... 

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