Diluted Acetic Acid

The residual liquid in the flask is a dilute alkaline solution of sodium acetate. To liberate the acetic acid, add dilute sulphuric acid until the solution is definitely acid to litmus, and then distil off about 20 ml. Perform on this aqueous distillate the tests for acetic acid given on p. 347-... 

The alkylidene dimethone (dimedone) (I) upon boiling with glacial acetic acid, acetic anhydride, hydrochloric acid and other reagents frequently loses water and passes into a substituted octahydroxanthene or the anhydride (II), which often serves as another derivative. The derivatives (I) are soluble in dilute alkali and the resulting solutions give colourations with ferric chloride solution on the other hand, the anhydrides (II) are insoluble in dilute alkali and hence can easily be distinguished from the alkylidene dimedones (I). 

Step 2 The Boc protecting group is removed by treatment with hydrochloric acid m dilute acetic acid After the resin has been washed the C terminal ammo acid IS ready for coupling... 

The workup is accomplished simply by dilution with water and extraction with ether. Alternately, the reaction mixture can be neutralized with acetic acid before dilution with water, etc. 

Hydrolysis of the ketal group with hot acetic acid or dilute aqueous methanolic sulfuric acid affords the 5a-hydroxy-6 -methyI-3-ketone (8). 

Consider the dissociation of a weak electrolyte, such as acetic acid, in dilute aqueous solution ... 

Procedure. To 10 mL of a solution (Note 2) containing from 1 to 10 pg of nickel(II) add 5mL of a phthalate or acetate (ethanoate) buffer of pH 6.0 or, if the sample solution is acidic, use dilute ammonia to adjust the pH. To this solution now add 15mL of a chloroform solution of dithizone (7 x 10-5M) and 1,10-phenanthroline (3 x 10-5M). Shake the phases for five minutes in a... 

Hydroxyquinaldine (2-methyloxine) is a pale yellow, crystalline solid, m.p. 72 °C it is insoluble in water, but readily soluble in hot ethanol, benzene, and diethyl ether. The reagent is prepared by dissolving 5 g of 8-hydroxyquinaldine in 12 g of glacial acetic acid and diluting to 100 mL with water the solution is stable for about a week. 

Note. The reagent is prepared by dissolving 5g 8-hydroxyquinaldine in 12 g glacial acetic (ethanoic) acid and diluting to 100 mL with water. 

Add 3 mL of reagent solution (dissolve 5g reagent in 12 g glacial acetic acid and dilute to 100 mL with water) for every 10 mg of magnesium present and then add concentrated ammonia solution until the pH is at least 9.3 (or no further precipitate forms). Heat at 60- 80 °C for 20 minutes, filter and wash the precipitate with hot water. Dry at 130-140 °C and weigh as Mg(C10H8ON)2 (Section 11.31). 

Hydroxyquinoline ( oxine) solution, 5 per cent. Dissolve 5.0 g oxine in 12 g glacial acetic acid and dilute to 100 mL with distilled water. 

Basically, most processes for the commercial production of PETN involve pouring PE into 98+% nitric acid (sp gr 1.50—1.52g/cc) at a temp not exceeding 25°. Since PETN is only slightly sol in nitric acid it ppts near the end of the nitration. The ppt is then filtered, washed with water, neutralized with Na2C03 soln, and recrystd from acet. In some processes the nitric acid is diluted with water after nitration. This is believed to keep some of the impurities in soln... 

The mechanism of decarboxylation of acids containing an amino substituent is further complicated by the possibility of protonation of the substituent and the fact that the species NH2ArCOOH is kinetically equivalent to the zwitterion NHj ArCOO. Both of these species, as well as the anion NH2 ArCOO" and even NH3 ArCOOH must be considered. Willi and Stocker644 investigated by the spectroscopic method the kinetics of the acid-catalysed decarboxylation of 4-aminosalicyclic acid in dilute hydrochloric acid, (ionic strength 0.1, addition of potassium chloride) and also in acetate buffers at 20 °C. The ionisation constants K0 = [HA][H+][H2A+] 1 (for protonation of nitrogen) and Kx = [A"][H+] [HA]-1, were determined at /i = 0.1 and 20 °C. The kinetics followed equation (262)... 

It is obvious that many carboxylic acids of the formulas RCH2COOH and RR CHCOOH can be synthesized by this method (for some other ways of preparing such acids, see 10-106, 10-108, and 10-109). Another important example is the acetoacetic ester synthesis, in which Z is COOEt and Z is COCH3. In this case the product can be decarboxylated with acid or dilute base (12-38) to give a ketone or cleaved with concentrated base (12-41) to give a carboxylic ester and a salt of acetic acid ... 

Solution IV Dissolve 300 mg ninhydrin in 10 ml glacial acetic acid and dilute... 

P 67] A stock standard solution of benzophenone in 2-propanol (0.5 M) with a drop of glacial acetic acid was diluted to give further standard solutions of 0.1-0.4 M [72, 74]. These solutions were stored at room temperature, protected from exposure to light and were employed for a device having an optical path of 50 pm. When using a second generation device with a 500 pm path, the stock solution concentration was reduced to 0.05 M. 

A laboratory test is carried out into the extraction of acetic acid from dilute aqueous solution, by means of methyl iso-butyl ketone, using a spray tower of 47 mm diameter and 1080 mm high. The aqueous liquor is run into the top of the tower and the ketone enters at the bottom. 

The same reaction can be applied, not only to the aromatic parent substances, the hydrocarbons, but also to all their derivatives, such as phenols, amines, aldehydes, acids, and so on. The nitration does not, however, always proceed with the same ease, and therefore the most favourable experimental conditions must be determined for each substance. If a substance is very easily nitrated it may be done with nitric acid sufficiently diluted with water, or else the substance to be nitrated is dissolved in a resistant solvent and is then treated with nitric acid. Glacial acetic acid is frequently used as the solvent. Substances which are less easily nitrated are dissolved in concentrated or fuming nitric acid. If the nitration proceeds with difficulty the elimination of water is facilitated by the addition of concentrated sulphuric acid to ordinary or fuming nitric acid. When nitration is carried out in sulphuric acid solution, potassium or sodium nitrate is sometimes used instead of nitric acid. The methods of nitration described may be still further modified in two ways 1, the temperature or, 2, the amount of nitric acid used, may be varied. Thus nitration can be carried out at the temperature of a freezing mixture, at that of ice, at that of cold water, at a gentle heat, or, finally, at the boiling point. Moreover, we can either employ an excess of nitric acid or the theoretical amount. Small scale preliminary experiments will indicate which of these numerous modifications may be expected to yield the best results. Since nitro-compounds are usually insoluble or sparingly soluble in water they can be precipitated from the nitration mixture by dilution with water. 

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