Sodium bicarbonate solution test

Sodium azide, 918, 919 Sodium benzenesulphonate, 548,549 Sodium bicarbonate solution test, 360, 1071 ... 

For alcohols of b.p. below 150°, mix 0- 5 g. of 3-nitrophthalic anhydride (Section VII,19) and 0-5 ml. (0-4 g.) of the dry alcohol in a test-tube fitted with a short condenser, and heat under reflux for 10 minutes after the mixture liquefies. For alcohols boiling above 150°, use the same quantities of reactants, add 5 ml. of dry toluene, heat under reflux until all the anhydride has dissolved and then for 20 minutes more remove the toluene under reduced pressure (suction with water pump). The reaction product usually solidifies upon cooling, particularly upon rubbing with a glass rod and standing. If it does not crystallise, extract it with dilute sodium bicarbonate solution, wash the extract with ether, and acidify. Recrystallise from hot water, or from 30 to 40 per cent, ethanol or from toluene. It may be noted that the m.p. of 3-nitrophthalic acid is 218°. 

Benzoates. Dissolve 0-5 g. of the amino acid in 10 ml. of 10 per cent, sodium bicarbonate solution and add 1 g. of benzoyl chloride. Shake the mixture vigorously in a stoppered test-tube remove the stopper from time to time since carbon dioxide is evolved. When the odour of benzoyl chloride has disappeared, acidify with dilute hydrochloric acid to Congo red and filter. Extract the solid with a little cold ether to remove any benzoic acid which may be present. RecrystaUise the benzoyl derivative which remains from hot water or from dilute alcohol. 

The solution will then contain the free acid and the hydrochloride of the base either of these may separate if sparingly soluble. If a sohd crystallises from the cold solution, filter, test with sodium bicarbonate solution compare Section 111,85, (i) and compare the m.p. with that of the original compound. If it is a hydrolysis product, examine it separately. Otherwise, render the filtrate alkahne with sodium hydroxide solution and extract the base with ether if the presence of the unchanged acyl canpound is suspected, extract the base with weak acid. Identify the base in the usual manner (see Section IV, 100). The acid will be present as the sodium salt in the alkaline extract and may be identified as described in Section IV,175. 

Group I. This includes the lower members of the various homologous series (4-5 atoms in a normal chain) that contain oxygen and/or nitrogen in their structures they are soluble iu water because of their low carbon content. If the compound is soluble in both water and ether, it would also be soluble in other solvents so that further solubility tests are generally unnecessary the test with sodium bicarbonate solution should, however, be performed (see Section XI,6). 

An indication whether a water-insoluble compound is an acid or a phenol (or enol) will be obtained from the Solubihty Tests water-soluble acids will bberate carbon dioxide from 5 per cent, sodium bicarbonate solution see Section III,85,(i). ... 

The presence of simple water-insoluble phenols (or enols) will be indicated by the insolubility in 5 per cent, sodium bicarbonate solution. Further evidence will be obtained by carrying out the following tests. 

Add 5 mL of an aqueous 10% sodium bicarbonate solution, shake to mix (vent CO2 through stopcock) and test pH with testpaper. If not alkaline (pH 7.5-8) add stepwise additional 1 mL portions until alkaline. 

Detection of Potassium Nitrate.—About 5 grams of the extract (15 grams if liquid) are diluted with 20 c.c. of distilled water and the liquid mixed with 10 c.c. of 20% sulphuric acid and distilled, the distillate being collected in 10-20 cc. of a dilute sodium bicarbonate solution. The distillation is continued until the substance begins to bump, the distillate being then evaporated to small volume, acidified with dilute sulphuric acid and tested for nitric acid by means of ferrous sulphate or brucine in the usual way (see also p. 7). 

Peracetic acid solution (107.7 g of 9.0 wt % peracetic acid) at ambient temperature was added to a reaction flask equipped with mechanical stirrer and thermocouple, nitrogen inlet adapter and addition funnel. A 20 wt % stock solution of the dienolsilyl ether of codeinone (41.7 g) was added through the addition funnel over a period of about 5 min and the temperature of the contents maintained at 28°C. The batch was stirred at 22°C for at least 3 hours. In order to test reaction completeness, a small sample was withdrawn from the batch and quenched with saturated sodium bicarbonate solution, and extracted with ethyl acetate. The EtOAc layer was spotted onto a TLC plate and subsequently checked for the disappearance of starting dienolsilyl ether of codeinone. The TLC mobile phase was a mixture of 95 5 of dichloromethane and methanol plus 3-5 drops of concentrated ammonium hydroxide. If the reaction was adjudged incomplete, the mixture was stirred at the same temperature for an additional 2 hours then analyzed by TLC again. Alternatively completion of the reaction was pushed by the addition of 10 g of peracetic acid (9.0 wt %) and stirring for an additional 1 h (analysis was then once more performed using TLC). 

Test Preparation (See Chromatography, Appendix IIA.) Dissolve 2.00 g of sample in 8.0 mL of 5% sodium bicarbonate solution, and mix the solution thoroughly with 10.0 g of chromatographic siliceous earth (Celite 545, Johns-Manville, or equivalent). Transfer the mix into a 250- x 25-mm chromatographic tube that has a fritted-glass disk and a Teflon stopcock at the bottom and a reservoir at the top. Pack the... 

Results Distilled water (test tube No. 1) made suds very easily and didn t require many drops of soap solution or much shaking. Tap water (test tube No. 2) made suds easily or else not at all, depending upon what part of the country you live in. The more minerals dissolved in your water, the less easily suds form. The calcium bicarbonate solution (test tube No. 3) made very few suds, and those that it did make disappeared very quickly. The other calcium bicarbonate solution (test tube No. 4) made very good suds after you boiled it and after a white precipitate separated out. The magnesium sulfate solution (test tube No. 5) formed few suds. The other magnesium sulfate solution (test tube No. 6) made goods suds after you added sodium tetraborate or potassium carbonate. 

Paper sheets individually supported on the webbed polyester sheets were immersed in a water bath for a minimum of 1 h. The washing procedure was repeated three times. Test papers that were to be further subjected to a neutralization treatment were immersed in a 10 2 M sodium bicarbonate solution for 1 h. Subsequently, these test papers were also washed in three changes of water. The chemical treatments, as well as the washings, were intermittently punctuated with gentle agitation. Finally, the treated paper sheets, while still supported on nonwoven polyester, were placed on blotting papers to drain and then were air dried between acid-free paper. 

The stabilities of bleached kraft paper samples containing copper and iron species were compared before and after neutralization. Paper samples with copper(II) and iron(II) species adsorbed from their sulfate solutions were treated with sodium bicarbonate solution to neutralize acidic species. Excess sodium bicarbonate was washed away. Thus, no extraneous cations were introduced in this treatment, and the formation of any complex with the transition metal species was thereby precluded. Therefore, any stabilization observed as a result of this treatment can be ascribed only to the neutralization of acidic species in the test paper. A decrease in acidic content would inevitably enhance the stability of paper toward acidic hydrolysis. The stability of the test samples may be further influenced if the neutralization treatment affects the nature of the catalytic species or if the acidic species in paper also participate in the oxidation process. 

Test the solubility of your sample in toluene and in hot water and note the peculiar character of the aqueous solution when it is cooled and when it is then rubbed against the tube with a stirring rod. Note also that the substance dissolves in cold sodium bicarbonate solution and is precipitated by addition of an acid. Compare a tablet of commercial aspirin with your sample. Test the solubility of the tablet in water and in toluene and observe if it dissolves completely. Compare its behavior when heated in a melting point capillary with the behavior of your sample. If an impurity is found, it is probably some substance used as binder for the tablets. Is it organic or inorganic To interpret your results, consider the mechanism whereby salicylic acid is acetylated. 

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