Sulfuric acid dilution

Ceric sulfate, O.IA Ce(lV) to Ce(lll). Dissolve 63.26 g of cerium(lV) ammonium sulfate dihydrate in 500 mL of 2N sulfuric acid. Dilute the solution to 1 L and standardize against the... 

Table 4. Plant Corrosion Test in Sulfuric Acid Dilution with Recirculated Phosphoric Acid ...

C. Thymoquinone.—The wet aminothymol thus prepared is immediately dissolved in no cc. of concentrated sulfuric acid diluted to 4 1. and contained in a 12-I. flask. To this solution is added 150 g. of sodium nitrite (2.18 moles), in 5-10-g. portions, with shaking after each addition. The resulting mixture is heated to 60° on a steam bath, with occasional shaking, for half an hour (Note 5), and is then distilled in a current of steam, by means of the apparatus described in Org. Syn. 2, 80 (Note 6). All the thymoquinone passes over with the first 3 1. of distillate it solidifies on cooling, and is filtered with suction (Note 7), washed, and dried at room temperature. The yield is 80-87 g. (73-80 per cent of the theoretical amount) of bright yellow crystals, melting at 43-45° (Note 8). 

The residue (12 g) which contains the 18-iodo-18,20-ether is dissolved in 200 ml of acetone, 5 g of silver chromate is added Note 3) and after cooling to 0°, 11.8 ml of a solution of 13.3 g of chromium trioxide and 11.5 ml of concentrated sulfuric acid, diluted to 50 ml with water is added during a period of 5 min. After an additional 60 min, a solution of 112 g of sodium acetate in 200 ml of water is added and the mixture diluted with benzene (400 ml), filtered and the benzene layer separated. The aqueous phase is reextracted with benzene, washed with half-saturated sodium chloride solution, dried and evaporated to yield 11.2 g of a crystalline residue. Recrystallization from ether gives 7.2 g (72%) of pure 3/5, 1 la, 20/5-trihydroxy-5a-pregnan-18-oic acid 18,20 lactone 3,11-diacetate mp 216-218°. 

In a 2-1. flask are placed 375 g. of commercial sodium dichromate, 225 cc. of water, and 300 g. of dichlorohydrin (b. p. 68-75°/i4 mm.). The flask is set in a water bath and equipped with a thermometer and mechanical stirrer. The contents are vigorously stirred, and 450 g. of sulfuric acid, diluted with 115 g. of water, are introduced during the course of seven to eight hours. It is convenient to add the acid at ten-minute intervals. The temperature is kept between 20° and 250 during the entire reaction this is accomplished by adding a little ice to the water bath from time to time. The stirring is continued for sixteen to seventeen hours after all the acid has been added as there is very little heat evolved during this part of the reaction, the water bath may be allowed to come to room temperature. 

In a recent document [25] presenting techniques adopted by the French for pollution prevention, a new process modification for steam segregation and recycle in phosphoric acid production is described. As shown in Figure 9, raw water from the sludge/fluorine separation system is recycled to the heat-exchange system of the sulfuric acid dilution unit and the wastewater used in plaster manufacture. Furthermore, decanted supernatant from the phosphogypsum deposit pond is recycled for treatment in the water filtration unit. The claim was that this process modification permits an important reduction in pollution by... 

Rhenium can be analyzed by various instrumental techniques that include flame-AA, ICP-AES, ICP-MS, as well as x-ray and neutron activation methods. For flame-AA analysis the metal, its oxide, or other insoluble salts are dissolved in nitric acid or nitric-sulfuric acids, diluted, and aspirated directly into nitrous oxide-acetylene flame. Alternatively, rhenium is chelated with 8-hydroxy quinoline, extracted with methylisobutyl ketone and measured by flame-AA using nitrous oxide-acetylene flame. 

Elemental composition Ag 75.26%, Cl 24.74%. The salt is dissolved in concentrated sulfuric acid, diluted, and analyzed for silver (see Silver). Solid powder may be characterized by its physical properties and its reaction with cyanide ion, forming the complex ion [Ag(CN)2]. ... 

By nitric add and sulfuric add. The oxidation of ethylene sulfide with concentrated nitric acid leads to eulfoacetic add, HOaSCHjOOjH. and other condensed acids.8 Sulfuric acid, dilute or concentrated, appears to have only a polymerizing influence.18... 

V vs. Ag/AgCl in acid has been described [132]. The assay requires the extraction of the compound from a tablet into the 0.5 M sulfuric acid, dilution, and direct polarographic assay of an aliquot of this solution. The assay is accurate, sensitive, and, since it does not require the removal of insoluble matter, more rapid than the spectrophotometric procedures. 

The Extrelut cleanup method is suitable for most foodstuffs, such as cheese, yogurt, and other samples that tend to form emulsions during extraction. The prepacked or refilled Extrelut column in a plastic tube consists of a wide-pore kieselgel column. A sample is homogenized in 0.5 N sulfuric acid, diluted with water, and applied onto the Extrelut column for at least 15 min. The absorbed preservatives are eluted with a chloroform - isopropanol (9 1) mixture, and the elu-ate is collected and evaporated carefully nearly to dryness. The last few milliliters of solvent are removed with a gentle flow of nitrogen to prevent substantial losses of BA and SA, which have relatively high vapor pressures. The residue is transferred with methanol into a 10-ml volumetric flask and diluted to volume with methanol. To speed up the dissolution, the use of an ultrasonic bath is recommended. The filtered extract is analyzed on a /zBondaPak Cl8 column, with a... 

Sulfuric acid, dilute Acetates, CH3COO- Evolution of acetic acid (vinegar-like odor) concentrated sulfuric acid also evolves sulfur dioxide under mild heating... 

Potassium chromate Potassium iodide Sulfuric acid, dilute Hydrogen sulfide gas Potassium cyanide... 

Standard Preparations Dissolve 338.5 mg of mercuric chloride, in about 200 mL of water in a 250-mL volumetric flask, add 14 mL of 1 2 sulfuric acid, dilute to volume with water, and mix. Pipet 10.0 mL of this solution into a 1000-mL volumetric flask containing about 800 mL of water and 56 mL of 1 2 sulfuric acid, dilute to volume with water, and mix. Pipet 10.0 mL of the second solution into a second 1000-mL volumetric flask containing 800 mL of water and 56 mL of 1 2 sulfuric acid, dilute to volume with water, and mix. Each milliliter of this diluted stock solution contains 0.1 pig of mercury. Pipet 1.25, 2.50, 5.00, 7.50, and 10.00 mL of the last solution (equivalent to 0.125, 0.250, 0.500, 0.750, and 1.00 ptg of mercury, respectively) into five separate 150-mL beakers. Add 25 mL of aqua regia to each beaker, cover with watch glasses, heat just to boiling, simmer for about 5 min, and cool to room temperature. Transfer the solutions into separate 250-mL volumetric flasks, dilute to volume with water, and mix. Transfer a 50.0-mL aliquot from each solution into five separate 150-mL beakers, and add 1.0 mL of 1 5 sulfuric acid and 1.0 mL of a filtered solution of 1 25 potassium permanganate solution to each. Heat the solutions just to boiling, simmer for about 5 min, and cool. 

Ferrous Sulfate Solution Dissolve 44 g of ferrous sulfate (FeS04-7H20) in ] N sulfuric acid, dilute to 100 mL with 1 N sulfuric acid, and mix. Use within 5 days of preparation. 

Standard Arsenic Solution Accurately weigh 132.0 mg of arsenic trioxide that has been previously dried at 105° for 1 h, and dissolve it in 5 mL of a 1 5 sodium hydroxide solution. Neutralize the solution with 2 N sulfuric acid, add 10 mL in excess, and dilute to 1000.0 mL with recently boiled water. Transfer 10.0 mL of this solution into a 1000-mL volumetric flask, add 10 mL of 2 N sulfuric acid, dilute to volume with recently boiled water, and mix. Use this final solution, which contains 1 pig of arsenic in each milliliter, within 3 days. 

Sulfuric acid, dilute h,so4 — chemical supply house... 

A solution of 200 g. (1.03 moles) of a-methyl-d-mannoside (Org. Syn. Coll. Vol. 1, 1st Ed. (1932), p. 362 2nd Ed. (1941), p. 371) in 3.2 1. of 2 N sulfuric acid (178 cc. concentrated sulfuric acid diluted to 3.2 1.) is steam-distilled from a 5-1. flask for one hour. The flask is heated externally during this time so that the volume of the solution remains constant. The mixture is transferred to a 2- or 3-gal. crock, 10 g. of decolorizing charcoal (Norite) is added, and the solution is rapidly stirred while it is neutralized (litmus) by the addition of barium carbonate (Note 1). 

The nitrate ion activities in the aqueous phase were measured with a nitrate ion selective electrode taking into account the presence of high hydrogen ion concentration by calibration of the nitrate electrode with nitric acid. The nitrate ion concentration in the organic phase owing to the extraction of neodymium complexes by HDEHP was determined by back-extraction of the organic phase with 3M sulfuric acid, dilution, and analysis with a nitrate ion electrode calibrated for different nitrate and sulfate concentrations. The amount of the nitrate species extracted into the organic phase increases as the initial neodymium nitrate concentration increases. 

Before being charged to an alkylation unit, olefin streams are normally treated for removal of sulfur compounds. The type of treating used depends for the most part on the amount and kind of sulfur compounds present. Quantities are normally reported in parts per million units. According to Industry sources, estimates of the amount of sulfuric acid diluted lie in a range of 15 to 60 pounds per pound of sulfur in the feed. A very commonly used factor is 20 pounds per pound. In the case of methyl mercaptan, if one assumes a mole for mole reaction occurs and that the reaction products are soluble in the acid and do not titrate, then the calculated amount of acid diluted is 53.7 pounds per pound of mercaptan sulfur (dilution range 98.5 to 90.0%). This is a very severe assumption however commercial tests indicate about 45 pounds per pound and this is probably more realistic. Somewhat lower dilution rates are normally assumed for H2S and COS, typically ranging between 15 and 18 pounds per pound of sulfur present. 

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