Acid Hydrochloric Fuming

A round flask (250 c.c.) is fitted with an air-condenser. The phosphorous pentachlorlde is introduced from the bottle and weighed by difference. The operation must be conducted in the fume-cupboard. The benzoic acid is then added, and the air-condenser attached to the flask. The action begins almost immediately, and clouds of hydrochloric fumes are evolved. The whole contents become liquid and consist of benzoyl chloride (b. p. 200 ), phosphorous oxychloiide (b. p. 107°), and unchanged pentachloride. Most of the oxychloride may be removed by distilling in vacuo on the water-bath. The remainder is fractionated at the ordinary pressure and collected at 190-200°. Yield, 20 —25 giams. 

Manufacture. ///-Hydroxybenzoic acid was first obtained by the action of nitrous acid on / -aminobenzoic acid (48). It is more conveniendy prepared by the sulfonation of benzoic acid with fuming sulfuric acid. The resulting ///-sulfobenzoic acid is mixed with salt and fused with caustic soda at 210—220°C. The fusion melt is dissolved in water and acidified with hydrochloric acid to precipitate the cmde product. Final purification is generally achieved by recrystallization from water. 

Acid, Hydrochloric. See Hydrochloric Acid Acidity In Acids. If the acid used in manuf of ezpls, propellants etc is white nitric, its acidity is detd by dissolving (without loss of fumes) a weighed sample in w and titrating the resulting soln with std NaOH soln in presence of an indicator such as methyl red... 

Nitric Acid.—-The commercial cone, acid generally contains about 70% HN03. Fuming nitric acid (see p. 512) containing about 95% HN03 (D. 1-5) is available commercially. Usual impurities oxides of nitrogen, sulphuric acid, hydrochloric acid, chlorine and iodine. 

In this method, portions (2 g) of the plant material were digested in 30 ml of digestion acid until fumes of nitric acid are produced then the solution is cooled, and diluted to 50 ml in 15% hydrochloric acid-10% sulfuric acid vlv. This solution was used for analysis. Recovery studies were made by spiking the digestion acid or sample just prior to the digestion procedure with varying amounts of standard solution. Quantification of the six elements was made from linear calibration curves verified by the method of standard additions. 

Phosphorus(V) sulfochloride is a colorless, fuming liquid with boiling point 125° and specific gravity 1.635. The alpha form solidifies at —40.8°, while the beta form solidifies at —36.2°.7 The compound hydrolyzes slowly in water and rapidly in alkaline solution. In water, the hydrolysis products are orthophosphoric acid, hydrochloric acid, and hydrogen sulfide. Phosphorus (Y) sulfochloride is soluble in benzene, carbon tetrachloride, carbon disulfide, and chloroform. It reacts with ethanol, yielding O-ethyl dichlorothiophosphate8 (synthesis 25). 

Welcher et al. [4] have described the analysis of cobalt-based alloys. Cobalt alloys may be dissolved according to the following procedure. Weigh 0.5000 g of sample into a PTFE beaker. Add 2 ml of water, 10 ml of concentrated hydrochloric acid and 5 ml of concentrated nitric acid. Warm the mixture for approximately thirty minutes. Add 2 ml of concentrated nitric acid and 5 ml of concentrated hydrochloric acid and reheat for a further thirty minutes. Cool, add 5 ml of hydrofluoric acid and fume to dryness. Add 5 ml of concentrated nitric acid and heat for ten minutes. Repeat with a further 5 ml of nitric acid. Add 10 ml of hydrochloric acid and reheat to boiling, cool and dilute to 100 ml. Standard conditions for the analysis of cobalt alloys are shown in Table 3. 

Hydrochloric acid (concentrated, fuming ). The commercial concentrated hydrochloric acid is a water-like solution with a characteristic smell, and is fuming owing to the evaporation of hydrogen chloride gas. It has a density of 1 19 g cm 3, contains 36 0 % (w/w) HC1 (or 0 426 g HC1 per ml), and is approximately 11 7 molar. The reagent should be stored far away from concentrated ammonia to prevent the formation of ammonium chloride fumes. It should be handled with care, using eye protection. 

Chromyl chloride fumes in air owing to the fact that it is decomposed by water into chromic and hydrochloric acids. The fumes when introduced into a Bunsen flame exhibit a characteristic spectrum. When sufficiently purified by distillation, and free from access to moisture, chromyl chloride may be kept unchanged for a considerable time, though on very long standing some dark coloured solid— probably a polymeride—is deposited. This tendency to polymerise is also suggested by the results of cryoscopic molecular weight determinations in carbon tetrachloride, tin tetrabromide, or antimony pentaehloride. 

EXPLOSION and FIRE CONCERNS a flammable liquid NFPA rating Health 2, Flammability 2, Reactivity 1 explosive reactions with barium peroxide, boric acid, hydrochloric acid + water, potassium permanganate incompatible with 2- amino ethanol, aniline, glycerol, hydrogen fluoride, permanganates, sodium hydroxide, sodium peroxide, sulfuric acid, water when heated to decomposition it emits toxic fumes such as acetic acid and carbon monoxide use carbon dioxide, dry chemical, water mist, or alcohol foam for firefighting purposes. 

Pure aqueous hydrochloric acid has, when concentrated, a Sp. G. of 1 21, and fumes strongly when exposed to the air, the gas constantly escaping and uniting with the vapour which it meets. The acid even fumes when no denser than 1.13, and acid of from 1 14 to 1 16 is most convenient for common use, as there is not so much gas lost from it as from the strongest. It ought to be quite colourless if yellow, it contains perchloride of iron or free chlorine, probably both. The liquid is veiy acid and corrosive. When a rod dipped in aqua ammonias is brought near, very thick white fumes of sal ammoniac are formed. If... 

Our present knowledge of this class of acids is confined to the methyl and ethyl compounds, both of which may be isolated by dissolving the corresponding secondary phosphine in hydrochloric acid, adding fuming nitric acid and boiling the mixture. The silver salts are definite crystalline compounds, but free diethylphosphmic acid has not been obtained in the soHd state. 

K. Fischbeck and E. Einecke found that the cathodic polarization of ferrous, cuprous, calcium, and magnesium chromites produces chromic acid, whilst the other chromites are unaffected, and natural chrome ironstone behaves in a like manner, but other commercial chromites are reduced on cathodic polarization, and yield chromic acid on anodic polarization. Chromites behave as an intermediate electrode. 0. Unverdorben observed that chromyl fluoride, prepared by heating a mixture of fluorspar, lead chromate, and sulphuric acid, when passed into water, furnishes an aq. soln. of this oxide. The soln. was treated with silver nitrate, and the washed precipitate of silver chromate decomposed by hydrochloric acid. A. Mans said that anhydrous sulphuric acid or fuming sulphuric acid is not suited for the preparation because of its volatilization with the chromyl fluoride. 

Figure 2.1 A chemical plant in the industrial section of north Fort Worth explodes mtofhmtes in July 2005. sending toxic smoke hundreds of feet into the air. The blast and subsequent fire were fueled by a mixture of sulfuric acid, hydrochloric acid, ethanol, methanol, and isopropyl alcohol, with SO different chemicals used and stored in tanks at the plant. Injuries from exposure to the fumes were apparently limited by fortuitously strong winds that helped to dissipate the plume relatively quickly. Photo reprinted with permission, courtesy of David Bailey.

A piece of the metal of about 0.5 g is weighed and dissolved slowly with 30 ml nitric acid (A) and 10 ml hydrochloric acid (B) in a 100 ml beaker After dissolution, silicon is filtered off by using a medium size filter. To the filtrate 2 ml sulphuric acid (C) are added and the solution is boiled down until sulphuric acid starts fuming. The filter with the non dissolved silicon is dried at 110°C, the silicon is transferred from the filter onto a beaker cover and the filter is ashed in a platinum dish. After ashing, the silicon is introduced into the platinum dish. 5 ml hydrofluoric acid (D), 5 ml nitric acid (E) and 1 ml sulphuric acid (C) are added and one heats until the whole is dissolved. The boiled down filtrate is added to the solution in the dish and heated until the sulphuric acid starts fuming. After cooling off, 40 ml water are added and the solution is transferred into a 100 ml beaker. The final determination is carried out as described above. The accuracy is 15 for concentrations of the order of 10 Mg/g. The duration of the analysis is approximately 5 hours. 

The company s current ethylene capacity is 530 000 tonnes a year. Its ABS capacity is 50 000 tonnes per year. It also has a 100 000 tonnes per year LLDPE facility and has recently added another 120 000 tonnes per year PE facility. Its annual output of PVC, PS and PP are 27 000, 8300 and 12 000 tonnes, respectively. Shijinggou Integrated Chemical Plant of Jilin Chemical Industrial Group, an affiliate of the company, is a major polyoxymethylene (POM) producer in China with a POM capacity of 5000 tonnes per year. Other major products include aniline, sulphuric acid, fuming sulphuric acid, hydrochloric acid, concentrated nitric acid, caustic soda, sodium nitrate, sodium nitrite, calcium carbide, sodium bicarbonate, refined aluminium chloride, liquid sulphur dioxide, hydrogen peroxide, sulphur, commercial liquefied chlorine, ammonia,... 

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