Acid Hydrochloric Sublimed

Properties White powder anhydrous or containing variable amounts of water. D 6.6-6.9, mp 1127C, sublimes at 1800-1900C. Soluble in concentrated sulfuric acid, hydrochloric acid insoluble in water. Noncombustible. 

Mercuryill) chloride is obtained in solution by dissolving mercury(II) oxide in hydrochloric acid the white solid is obtained as a sublimate by heating mercury(II) sulphate and solid sodium chloride ... 

Q Preparation of 2-Acetyi-3-Methyi-5-(2-Oxo-2,5-Dihydro-4-Furyi)Benzo[b]Furan (3556 CB) (1) A suspension of 2 grams of the compound prepared according to (B) in 20 ml of concentrated hydrochloric acid, is heated to about 50°C, just until it dissolves. Thereafter it is heated for 2 minutes to 70°C, just until precipitation commences. The mixture is allowed to cool, diluted with water, filtered, the residue washed, dried, and sublimed at 200°C and 0.1 mm pressure, 1.4 grams of product (Yield 70%) Is obtained, MPc = 218°-221°C. A second sublimation produces a chemically pure product, MP = 221°-222°C. 

A solution of 10.0 grams of purified S-methyl ether of 2-thio-5-fluorouracil, MP 230° to 237°C, in 150 ml of concentrated aqueous hydrochloric acid (containing approximately 37% by weight HCI) was refluxed under nitrogen for 4 hours. The reaction mixture was then evaporated in vacuo. The crystalline brownish residue was recrystallized from water. The resulting recrystallized product was further purified by sublimation in vacuo at 190° to 200°C (bath temperature)/0.1 mm pressure. There was obtained 5-fluorouracil, in the form of colorless or pinkish-tan crystals, MP 282° to 283°C (with decomposition). 

This aromatic alcohol has been an effective preservative and still is used in several ophthalmic products. Over the years it has proved to be a relatively safe preservative for ophthalmic products [138] and has produced minimal effects in various tests [99,136,139]. In addition to its relatively slower rate of activity, it imposes a number of limitations on the formulation and packaging. It possesses adequate stability when stored at room temperature in an acidic solution, usually about pH 5 or below. If autoclaved for 20-30 minutes at a pH of 5, it will decompose about 30%. The hydrolytic decomposition of chlorobutanol produces hydrochloric acid (HC1), resulting in a decreasing pH as a function of time. As a result, the hydrolysis rate also decreases. Chlorobutanol is generally used at a concentration of 0.5%. Its maximum water solubility is only about 0.7% at room temperature, which may be lowered by active or excipients, and is slow to dissolve. Heat can be used to increase dissolution rate but will also cause some decomposition and loss from sublimation. Concentrations as low as 0.125% have shown antimicrobial activity under the proper conditions. 

The corresponding AfA -sulfonyldiimidazole, prepared from sulfonyl chloride and imidazole, is of surprisingly low reactivity in every respect. It forms stable crystals of m.p. 141 °C which can be sublimed in vacuum and recrystallized from ethanol without alcoholysis. Even in dilute aqueous hydrochloric acid hydrolysis occurs only very slowly. 

The 1,5-naphthalenedithiol can be further purified to a melting point of 120-121° by sublimation under high vacuum in a molecular still, followed by reprecipitation of the water-soluble disodium salt of the sublimate from excess hydrochloric acid. The pure compound obtained from 9.1 g. of product weighs 8.6 g. (76%). 

A solution of 0.005 mol of a sulfoxide, 2.26g (0.01 mol) of stannous chloride dihydrate, and 2.0 ml of concentrated hydrochloric acid in lOml qf methanol is refluxed for 2-22 hours. The mixture is cooled, diluted with 20 ml of water and extracted with two 25 ml portions of benzene. The dried extracts are evaporated in vacuo leaving virtually pure sulfide which can be purified by filtration of its solution through a short column of alumina and vacuum distillation or sublimation. Yields are 62-93%. 

Holmium chloride is obtained from rare-earth minerals. Recovery steps are discussed above (see Holmium). The rare-earth mineral is cracked by acid attack by heating with hydrochloric acid. The water-soluble chloride salt is filtered and separated from insoluble residues. The hydrated chloride salt is heated at 350°C in a current of hydrogen chloride to yield anhydrous H0CI3. Heating in air in the absence of hydrogen chloride yields holmium oxychloride, HoOCl. Hohnium chloride may be purified by distdlation or vacuum sublimation. 

Orange yellow triclinic crystals or fluffy powder hygroscopic density 3.111 g/cm3 at 15°C sublimes at 64°C with decomposition melts at 101°C at 16 atm hydrolyzes in water soluble in ethanol, carbon tetrachloride and benzene soluble in concentrated hydrochloric acid but hydrolyzes in dilute acid. 

White monoclinic crystals hygroscopic density 2.80 g/cm sublimes at 331°C triple point 437°C vapor pressure 1 torr at 190°C critical temperature 504.85°C critical pressure 56.95 atm critical volume 319 cm /mol decomposed by water soluble in alcohol, ether, and concentrated hydrochloric acid. 

When Davy allowed oxymuriatic acid gas (chlorine) to react with moist sulfur, he obtained hydrogen chloride and oxygen. When he repeated the experiment, using Sicilian sulfur dried over calcium chloride, no oxygen gas was evolved and not a cubical inch of muriatic [hydrochloric] acid. . . and it was found that between 16 and 17 cubical inches of oxymuriatic acid gas [chlorine] had disappeared the whole of the sulfur was sublimed in the gas, and the liquor formed was of a tawny-orange colour [probably sulfur monochloride] (30). 

Robert Boyle stated in 1661, in his Sceptical Chymist, drat sal ammoniac is composed of muriatic (hydrochloric) acid and the volatile alkali (ammonia) and told how to separate the urinous and common salts (27). In 1716 Geoffroy the Younger demonstrated the composition of sal ammoniac and prepared it by sublimation (28, 29). In the same year, the Jesuit missionary Father Sicard described its preparation at Dam ire or Damayer, one mile from die City of El Mansura in the Nile Delta. In twenty-five large laboratories and several smaller ones, it was sublimed in glass vessels from die soot of die burned dung of camels and cows, to which, he said, had been added salt and urine. Lemere, the French consul at Cairo, described die process in 1719 for the Academy of Sciences in Paris, but made no mention of salt or urine (29, 30, 31). 

In the final purification, polonium is either dissolved in nitric acid and clectrodeposited onto platinum, or, better, gold (6, 25) the polonium is sublimed in a vacuum from the support metal or dissolved off the latter in dilute hydrochloric acid and precipitated as the monosulfide. Either hydrogen sulfide itself or the sulfide ion produced by the hydrolysis of thioacetamide may be used. The monosulfide is decomposed by heating under vacuum and the pure metal sublimed (14). 

Polonium tetraiodide (8) is a black solid which sublimes in nitrogen at 200°C with partial decomposition to the metal. It is formed from the elements at 40°C/1 mm, by treating polonium dioxide or hydroxide with 0.1 N hydriodic acid, and is precipitated from solutions of polonium(lV) in dilute hydrochloric acid on the addition of 0.1 N hydriodic acid. It is also obtained as a black sublimate by heating polonium dioxide in hydrogen iodide at 200°C a black addition compound (PoCVxHI) is formed in the cold. Polonium metal does not react with iodine dissolved in carbon tetrachloride, but with iodine dissolved in benzene it does react to some extent. 

Sesquiammino-boron Trichloride, 2BC13.3NH3, is also formed when dry ammonia gas is passed into liquid boron trichloride. The ammine does not fume on exposure to air, is less volatile than ammonium chloride, and may be sublimed without decomposition. Water decomposes it with formation of ammonium chloride, hydrochloric acid, and a borate. Besson 2 described a substance of composition 2BC13. 9NH3, which he obtained from boron phosphino-chloride and ammonia. This is not attacked by moist air and does not lose ammonia below 50° C., but water decomposes it immediately. 

Antimony pentachloride also unites with ammonia. Two products are formed by passing ammonia gas into cold antimony pentachloride, namely, triammino-antimony pentachloride, [Sb(NH3)3]Cl3, and tetranunino-antimony pentachloride, [Sb(NH3)1]Cl5.1 Triammino-antimony pentachloride is a red substance which decomposes on heating, with formation of a sublimate of composition 3NH4Cl.SbCl5. Tetram-mino-antimony pentachloride is a white volatile substance which decomposes into antimony ammonium chloride. NH4Cl.SbCls, on treatment with hydrochloric acid. 

Ammonium chloride is also formed by the action of hydrochloric acid on a soln. of ammonia or ammonium carbonate J. G. Qentele 5 made it by the double decomposition of ammonium bicarbonate and sodium, magnesium, calcium, and other chlorides H. J. E. Hennebutte and E. Mesnard, and A. Dubose and M. Heuzey, made it by the action of ammonium bicarbonate or sulphate on the double chloride of iron and calcium and it is made by the action of soln. of ammonium sulphate and sodium chloride when the soln. is cone, the crystals of sodium sulphate separate out and they are removed by suitable shovels the cone. soln. of ammonium chloride which remains is purified by crystallization. Ammonium chloride can also be obtained by sublimation from a dry intimate mixture of the same two salts. A. French made it by the joint action of air and steam on a mixture of salt, pyrites, and carbon or organic matter 2NaCl+4H20-j-S02+C-j-N2=2NH4Cl-i-Na2S04-i-C02. 

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