Sulfuric acid stock solution

For the past year Strike had been in consultation with contract labs over the making of phenylisopropyl alcohols using sulfuric acid and allylbenzenes (don t ask). The lab owners would listen patiently as Strike primitively described how and why an OH should go on the beta carbon. And without exception, the lab owners would point out to Strike that the best way to get an OH on the beta carbon would be to put a Br there first. But Strike don t wanna put a Br there first Strike would say, Strike wants the OH put on directly using sulfuric acid " The lab guys had to do what Strike said because Strike was holding all the money (...a fool and her money etc.). But out of curiosity Strike asked how they would get that Br on the beta carbon. Every one of them said it was simply a matter of using the 48% HBr in acetic acid. They even showed Strike their stock solutions (usually from Aldrich or Fisher). 

For these reasons there are limits to the extent to which the acid concentration can be increased gradually as the basicity of the amines decreases. Nevertheless, diazotization can be carried out without difficulty in 90-96% sulfuric acid. It has already been mentioned that nitrous fumes are given off as soon as nitrite is added to sulfuric acid of lower concentration, but solid sodium nitrite can be dissolved in 90-96% sulfuric acid at 0-10°C smoothly and without evolution of gas. Nitrosylsulfuric acid, N0+HS04, is formed. Directions for the preparation of 2 m nitrosylsulfuric acid are given by Fierz-David and Blangey (1952, p. 244), but sodium hydrogen sulfate crystallizes after some time from acid of this strength so that it is best to prepare a stock solution of 1 m sodium nitrite in 96% sulfuric acid, which is quite stable at room temperature. 

G.14 The sulfuric acid solution that is purchased for a stockroom has a molarity of 17.8 M all sulfuric acid solutions for experiments are prepared by dilution of this stock solution, (a) Determine the volume of 17.8 M H2S04 that must be diluted to 250 mL to prepare a... 

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. 

Standard Preparation Prepare the stock solution and the dilutions, as directed in the test, to obtain a solution containing 1 xg of mercury per milliliter. Transfer 1.0 mL of the final solution (1 xg of mercury) into a 50-mL beaker, and add 20 mL of water, 1 mL of 1 5 sulfuric acid, and 1 mL of a 1 25 solution of potassium permanganate. Cover the beaker with a watch glass, boil for a few seconds, and cool. 

Mercury Stock Solution Transfer 135.4 mg of mercuric chloride, accurately weighed, into a 100-mL volumetric flask, dissolve in and dilute to volume with 1 A sulfuric acid, and mix. Dilute 5.0 mL of this solution to 500.0 mL with 1 A sulfuric acid. Each milliliter contains the equivalent of 10 pig of mercury. 

To prepare a stock solution (500 ml.) mix appropriate stoichiometric amounts of standard 6 N sulfuric acid with standardized 10% aqueous Et4NOH (Eastman), evaporate to near dryness (70°, 15 mm.), and dissolve the residue in 10% aqueous [Et4N]OH to 500.0 ml. 

Stock iron solution Dissolve 392.8 mg ammonium iron (II) sulfate hexahydrate in a mixture of 2 ml concentrated sulfuric acid and 10 ml distilled water and add 0.05 N KMnO drop-wise till a faint pink colour persists and adjust the volume to 100 ml with deionised water. 

Prepare 100 mL of a 0.050 M solution of the waste acid from the 5.0 M solution obtained from Klein Chemicals. If your laboratory doesn t already have 0.050 M solutions of sulfuric acid and phosphoric acid, also prepare 100 mL of each of these from the stock solutions that you have. You will do the titration experiment three times, once with each of these three solutions. If your laboratory doesn t already have a 0.10 M solution of sodium hydroxide prepared, also prepare at least 250 mL of this solution. None of these need to be prepared with any great precision. 

Because of the expected better workup and disposal procedures, nitration in acetic acid was tried first. Stock solutions of4-(phenyl)morpholin-3-one in glacial acetic acid (2 m) and nitric acid (65%) in concentrated sulfuric acid (4.8 m) were used. For the reaction optimization, two disposable polypropylene syringes (3 mL capacity) were hlled with the different stock solutions and mounted on a syringe pump. The syringes were connected with the silicon micromixer that was connected with a residence time unit, a Teflon tube of known inner diameter and length. The flow of the syringe pump was adjusted according to the residence time required, the only variable. For simplicity, nitrations were carried out at room temperature. 

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