Water, acid running

Now cool the mixture thoroughly in ice-water, and run in over a period of 45 minutes a solution of 6 o g. of dry salicylic acid in 75 ml. of dry ether. When the addition of the acid to the stirred solution is complete, heat the mixture under reflux on the water-bath for 15 minutes to ensure completion of the reduction. Then thoroughly chill the mixture in ice-water, and hydrolyse any unused hydride by the slow addition of 50 ml. of ordinary undried ether, followed similarly by 75 ml. of dilute sulphuric acid. 

Place the distillate in a separating-funnel and extract the benzonitrile twice, using about 30 ml. of ether for each extraction. Return the united ethereal extracts to the funnel and shake with 10% sodium hydroxide solution to eliminate traces of phenol formed by decomposition of the benzenediazonium chloride. Then run off the lower aqueous layer, and shake the ethereal solution with about an equal volume of dilute sulphuric acid to remove traces of foul-smelling phenyl isocyanide (CaHjNC) which are always present. Finally separate the sulphuric acid as completely as possible, and shake the ether with water to ensure absence of acid. Run off the water and dry the benzonitrile solution over granular calcium chloride for about 20 minutes. 

Place a mixture of 53 g. of A.R. lactic acid (85-88 per cent, acid), 75 g. (85-5 ml.) of commercial anhydrous isopropyl alcohol, 300 ml. of benzene and 20 g. of Zeo-Karb 225/H (1) in a 700 ml. bolt-head flask, equipped with an automatic water separator (e.g., a large modified Dean and Stark apparatus with a stopcock at the lower end, see Fig. Ill, 126, 1) carrying an efficient reflux condenser at its upper end, and a mercury-sealed stirrer (alternatively, the hquid-sealed stirrer shown in Fig. 11,7,11, c. may be used). Reflux the mixture, with stirring, on a steam bath for 5 hours or until water no longer collects in appreciable amount in the water separator run off the water from time to time. Filter off the resin at the pump and wash it with two 25 ml. portions of benzene. Shake the combined filtrate and washings with about 5 g. of precipit-ated calcium... 

In a copper or iron kettle of 4-I. capacity is placed a solution of 200 g. of d-tartaric acid and 700 g. of sodium hydroxide in 1400 cc. of water. A 12-I. flask through which cold water is run is placed in the mouth of the kettle in order to prevent loss of water vapor, and the mixture is boiled gently over an open flame for four hours. The solution is now transferred to a 12-I. flask or crock and partially neutralized with 1400 cc. of commercial hydrochloric acid (density 1.19). To the still alkaline solution is now added just enough sodium sulfide to precipitate all the iron or copper which has been dissolved from the kettle (Note i). The filtered solution is then just acidified with hydrochloric acid, boiled to expel all hydrogen sulfide, and made very faintly alkaline to phenolphthalein with sodium hydroxide solution. To the hot solution is then added a concentrated solution of 300 g. of anhydrous calcium chloride which causes an immediate precipitation of calcium tff-tartrate and mesotartrate. 

The GBR resin works well for nonionic and certain ionic polymers such as various native and derivatized starches, including sodium carboxymethylcel-lulose, methylcellulose, dextrans, carrageenans, hydroxypropyl methylcellu-lose, cellulose sulfate, and pullulans. GBR columns can be used in virtually any solvent or mixture of solvents from hexane to 1 M NaOH as long as they are miscible. Using sulfonated PDVB gels, mixtures of methanol and 0.1 M Na acetate will run many polar ionic-type polymers such as poly-2-acrylamido-2-methyl-l-propanesulfonic acid, polystyrene sulfonic acids, and poly aniline/ polystyrene sulfonic acid. Sulfonated columns can also be used with water glacial acetic acid mixtures, typically 90/10 (v/v). Polyacrylic acids run well on sulfonated gels in 0.2 M NaAc, pH 7.75. 

Procedure. Dissolve a suitable weight of the sample of lead in 6M nitric acid add a little 50 per cent aqueous tartaric acid to clear the solution if antimony or tin is present. Cool, transfer to a separatory funnel, and dilute to about 25 mL. Add concentrated ammonia solution to the point where the slight precipitate will no longer dissolve on shaking, then adjust the pH to 1, using nitric acid or ammonia solution. Add 1 mL freshly prepared 1 per cent cupferron solution, mix, and extract with 5 mL chloroform. Separate the chloroform layer, and repeat the extraction twice with 1 mL portions of cupferron solution + 5 mL of chloroform. Wash the combined chloroform extracts with 5mL of water. Extract the bismuth from the chloroform by shaking with two 10 mL portions of 1M sulphuric acid. Run the sulphuric acid solution into a 25 mL graduated flask. Add 3 drops saturated sulphur dioxide solution and 4 mL of 20 per cent aqueous potassium iodide. Dilute to volume and measure the transmission at 460 nm. 

Next, we consider the effect of water. The runs 115, 111 B, 114 in Table 1 show that water causes the formation of tert-oxon urn ions, and our results suggest that as the amount of water increases, the number of these ions per mol of perchloric acid approaches 2. On this evidence one can conclude that the small amounts of tett-oxonium ions found by us in the absence of added water are probably due to residual water whose concentration we know to be less than ca., 10 4 M in our systems from conductivity and kinetic data. 

Experiment. Benzene from Phenylhydrazine.—Allow 5 g. of phenylhydrazine, dissolved in a mixture of 5 c.c. of glacial acetic acid and 10 c.c. of water, to run slowly into an ordinary distilling flask in which a solution of 25 g. of copper sulphate in 75 c.c. of water is heated to the boiling point. A downward condenser is attached to the flask. A vigorous evolution of nitrogen takes place and the benzene at once begins to distil with the steam. Collect and purify (as described on p. 286). Yield 2-3 g. 

Dimethylaniline (40 g. 0 33 mole) is dissolved in 250 c.c. of approximately 5 N-hydrochloric acid (one part of concentrated acid and one part of water) in a filter jar (capacity 1 1.) The jar is immersed in ice 200 g. of ice are dropped in, and then with good stirring—preferably with a mechanical stirrer—a cold solution of 25 g. of sodium nitrite in 100 c.c. of water is run in gradually from a dropping funnel (Fig. 51, p. 146). The temperature should not rise above 5° and no nitrous gases should be evolved. After the mixture has stood for one hour the orange-yellow hydrochloride is filtered thoroughly at the pump and washed several times with dilute hydrochloric acid (say 2 N). The salt is sufficiently pure for subsequent... 

In a 2-1. round-bottom flask, fitted with a stopper holding a dropping funnel and a mechanical stirrer, is placed a mixture of 275 cc. of concentrated nitric acid (sp. gr. 1.42) and 275 cc. of concentrated sulfuric acid (sp. gr. 1.84). This is cooled to io° in a freezing mixture, and 100 g. of benzyl cyanide (free from alcohol and water) are run in slowly, at such a rate that the temperature remains at about io° and does not exceed 20°. After all the benzyl cyanide has been added (about one hour), the ice bath is removed, the mixture is stirred for an hour and then poured on to 1200 g. of crushed ice. A pasty mass slowly separates more than half of this mass is -nitrobenzyl cyanide, the other constituents being o-nitrobenzyl cyanide, and a variable amount of an oil which resists hydrolysis apparently no dinitro compounds are formed. The mass is filtered on a porcelain funnel with suction, pressed well to remove as much oil as possible, and dissolved in 500 cc. of boiling alcohol (95 per cent). On cooling, -nitrobenzyl cyanide crystallizes the mother liquor, on distillation, gives an impure alcohol which can be used for the next run. Recrystallization from 550 cc. of 80 per cent alcohol (sp. gr. 0.86 to 0.87) yields 70 to 75 g. (50-54 per cent) of a product which melts at 115-116°. 

The inside capillary wall controls the electroosmotic velocity and provides undesired adsorption sites for multiply charged molecules, such as proteins. A fused-silica capillary should be prepared for its first use by washing for 15 min each (> 20 column volumes) with 1 M NaOH and 0.1 M NaOH, followed by run buffer ( —20 mM buffer). For subsequent use at high pH, wash for 10 s with 0.1 M NaOH, followed by deionized water and then by at least 5 min with run buffer.28 If the capillary is being run with pH 2.5 phosphate buffer, wash between runs with 1 M phosphoric acid, deionized water, and run buffer.29 When changing buffers, allow at least 5 min of flow for equilibration. For the pH range 4-6, at which equilibration of the wall with buffer is very slow, the capillary needs frequent regeneration with... 

Arsenic Oxidation States. A solution sample was taken 257 hr after initiation of the 300°C basalt + arsenic-doped deionized water experiment (Run D2-8, Table II). The data from arsenic oxidation state AAS analysis of the initial As(V)-doped water (0-hr sample) and of the 257-hr solution sample are given in Table HI. All detectable arsenic was in the +3 oxidation state [As(V) <15pg/L] in the 257-hr sample. Standard additions of AsGD) and As(V) to the 257-hr sample were quantitatively recovered. To desorb arsenic from particulates in this sample, an aliquot of the solution was treated with 5% hydrofluoric acid. The higher As(III) content of the treated 257-hr sample aliquot (110 vs. 61pg/L, Table HI) demonstrates that sorption occurred. Scanning transmission electron microscopic (STEM) analysis of the particulates indicated the presence of poorly crystallized high-iron illite . 

Wear nitrile rubber gloves, laboratory coat, and eye protection. Selenium powder may be mixed with sand and treated as normal refuse, as may the disulfide. Soluble selenites and selenates can be dissolved in water and run to waste, diluting with at least 50 times its volume of running water. Soda ash should be applied liberally to spills of selenium dioxide, selenic and selenous acids, and selenyl and selenium chlorides, which may then be mopped up cautiously with plenty of water wash down the drain, diluting greatly with at least 50 times its volume of water.16... 

The current density used is 50 amps, per dm.2 at 25 volts, and the nitric acid (density 1 4) mixed with one volume of water is run into the cathode compartment at the rate of 30 c.c. per hour. The reduced liquor on being evaporated in vacuo gives 80 per cent, of the calculated amount of hydroxylamine hydrochloride. 

When the reactive mixture is settled, the mixture splits. The lower, water acidic is poured through a run-down box into neutraliser 26, which has been loaded with a 40% solution of NaOH from batch box 25. 

Active scrubbers, which include pumps or other active components. These scrubbers generally circulate chemicals (such as water, acid, caustics, or organics) through a packed or trayed tower to absorb and/or condense hazardous materials from a vapor stream. The active components may run continuously, or only when material is released to the scrubber. This approach is most effective when the circulating fluid reacts with the material being adsorbed or condensed. 

After nitration was completed, 550 1. of water were run into the nitrator to reduce the solubility of the TNT in the acid, Mid the mixture was then transferred to a separator, where TNT was separated from the spent acid. 

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