Solutions pouring

Diazotisation. Dissolve 0 2 g. of the substance in about 5 ml. of dil. HCl, warming if necessary. Cool in ice-water and add sodium nitrite solution drop by drop the end of the diazotisation is marked by the complete decolorisation of the solution. Pour the diazonium solution into a cold solution of 2-naphthol in a considerable excess of NaOH solution a brilliant red dye is produced. 

Dimethylaminomethylindole (gramine). Cool 42 5 ml. of aqueous methylamine solution (5 2N ca. 25 per cent, w/v) contained in an 100 ml. flask in an ice bath, add 30 g. of cold acetic acid, followed by 17 -2 g. of cold, 37 per cent, aqueous formaldehyde solution. Pour the solution on to 23 -4 g. of indole use 10 ml. of water to rinse out the flask. Allow the mixture to warm up to room temperature, with occasional shaking as the indole dissolves. Keep the solution at 30-40° overnight and then pour it, with vigorous stirring, into a solution of 40 g. of potassium hydroxide in 300 ml. of water crystals separate. Cool in an ice bath for 2 hours, collect the crystalline solid by suction flltration, wash with three 50 ml. portions of cold water, and dry to constant weight at 50°. The yield of gramine is 34 g. this is quite suitable for conversion into 3-indoleacetic acid. The pure compound may be obtained by recrystaUisation from acetone-hexane m.p. 133-134°. 

Laudanine, C20H25O4N, was isolated by Hesse. The crude alkaloid is purified by recrj stallisation from dilute alcohol for the removal of small quantities of cryptopine, or it may be dissolved in acetic acid and the solution poured into dilute caustic soda, when this impurity is precipitated and laudanine may be recovered from the filtrate by addition of ammonium chloride. It still contains its isomeride laudanidine, which may be separated by repeated crystallisation of the hydrochlorides, laudanidine accumulating in the aqueous mother liquors. The base crystallises from dilute alcohol, or from a mixture of alcohol and chloroform in rhombic prisms, m.p. 166°, [a]o 0°. It dissolves in solutions of alkali hydroxides, fornung metallic derivatives, which are precipitated by excess of alkali, but is nearly insoluble in solution of ammonia. The salts crystallise well ... 

Reaction.—a too c.c. flask to a short upright condenser (see Fig. 86) and to the upper end of the condensei attach a vertical delivery tube, dipping into an ammoniacal cuprous chloride solution. Pour 2—3 c.c. of ethylene bromide into the flask with 4 times its volume of strong methyl alcoholic potash, which is prepared by boiling methyl alcohol with excess of caustic potash on the water-bath with upright condenser. On gently heating, a rapid evolution of acetylene occurs and the characteristic brown copper compound (C2H,Cu,HjO) is precipitated from the cuprous chloride solution. 

The moiten mass is then poured into ethanol at 96°C, the solution cooled down to 10°C and the precipitated product separated by centrifugation. The resulting product is dissolved in the minimum quantity of warm water and the solution poured into ethanol. 

The bottle should be clean and dry a little of the stock solution is introduced, the bottle well rinsed with this solution, drained, the remainder of the solution poured in, and the bottle immediately stoppered. If the bottle is not dry, but has recently been thoroughly rinsed with distilled water, it may be rinsed successively with three small portions of the solution and drained well after each rinsing this procedure is, however, less satisfactory than that employing a clean and dry vessel. Immediately after the solution has been transferred to the stock bottle, it should be labelled with (1) the name of the solution (2) its concentration (3) the data of preparation and (4) the initials of the person who prepared the solution, together with any other relevant data. Unless the bottle is completely filled, internal evaporation and condensation will cause drops of water to form on the upper part of the inside of the vessel. For this reason, the bottle must be thoroughly shaken before removing the stopper. 

Clean the graduated cylinder and use it to measure 25 mL of the hexamethylenediamine solution. Pour this solution into a different... 

A mixture of 0.33M of the acetophenone, 39 g of redistilled morpholine and 14.4 g sulfur is refluxed for 12 hours and the wrm solution poured into 175 ml hot ethanol. Cool to precipitate about 80% yield of the substituted phenylacetothiomorpholide (I). Mix about 50 g (I), 110 ml acetic acid, 16 ml sulfuric acid and 25 ml water and reflux 5 hours. Decant from the small amount of tar formed with stirring into 850 ml water. Filter, wash the precipitate with water and heat the precipitate with 225 ml 5% aqueous NaOH. Filter and acidify the filtrate with dilute HCI to give about 80% yield of the substituted phenylacetic acid (II). Mix about 21 g (II) and 25 g phosphorus pentachloride (caution), and after the initial reaction subsides, warm on the steam bath 10 minutes. Distill under reduced pressure to remove the POC1 and gradually add the residue to ice cold concentrated NH4OH. Filter, wash precipitate with water and air dry (can recrystallize from benzene with a little ethanol added) to get about 18 g (85%) of the substituted phenyl-acetamide (111). (Ill)... 

The dilatometers are emptied as follows.The dilatometer, cooled in ice to below 10 °C, is inclined carefully over a small beaker, the capillary is lifted from the dilatometer, the polymer solution poured into a beaker and the capillary and dilatometer bulb washed... 

Water Transfer 5 mL acetic acid, or enough to adjust sample pH between 3 and 4, and 1 g Kl, and 1 ml starch solution pour in sample and mix. lodometric titration 20 ig/L No data APHA 1998 (Method 4500-CL02-B)... 

A more convenient method of preparation is described by Briggs, according to which, the eobaltous carbonate is dissolved in the smallest possible quantity of nitric acid, the solution poured into aqueous ammonia containing ammonium carbonate, and air drawn through the liquid for some time. It is then heated on a water-bath with frequent additions of ammonium carbonate, when the colour of the liquid changes to deep red, and allowed to stand till crystallisation is complete. The water of hydration is not removed on heating to 100° C., nor in vacuo over sulphuric acid at ordinary temperature.3... 

The step 1 product (0.412 g) was dissolved in 10 ml of chlorobenzene and treated with iron(III) chloride (0.46 g) in 10 ml of chlorobenzene and then heated to 65°C for 48 hours. After cooling to ambient temperature 15 ml of chlorobenzene was added and the solution poured into 200 ml methanol where it was ultrasonicated for 2 minutes. After being stirred at ambient temperature for 1 hour, a precipitate was isolated that was added to a mixture of 200 ml of methanol and 50 ml 12 M ammonium hydroxide solution. The mixture was then ultrasonicated for 30 minutes and a dark red solid precipitated. The solid was purified by Soxhlet extraction using methanol for 3 hours, hexane for 24 hours, heptane for 24 hours, and then chlorobenzene for 24 hours. After filtration 0.12 g of product was isolated as a dark red solid having an M = 16,550 Da, Mw = 65,300 Da, with a polydispersity of 3.95. 

Electrical Conductance of Acid Solutions. Pour prepared acid solutions into three dry beakers and check whether they conduct an electric current. Record the ammeter readings. On the basis of these experiments, arrange the acids in a series according to their activity. 

Electrolysis of a Copper(II) Chloride Solution. Pour a 5% copper chloride solution into U-tube 3 (Fig. 52). Use carbon bars as electrodes. Fit small pieces of rubber tubes onto carbon electrodes 4 so that the ends of the electrodes protrude by 2 cm. Secure the electrodes with the aid of two stoppers do not close the tube tightly). 

Prepare 20 ml of a solution of the obtained compound saturated at room temperature. Pour 3 ml of the solution into each of three test tubes. Add to the first tube 1 ml of a 1 N sulphuric acid solution, one drop of silver nitrate, and one drop of a 1 N manganese sulphate solution. Heat the tube. Add to the second tube 1 ml of a 1 A chromium sulphate solution and 2 ml of a 1 A sodium hydroxide solution. Pour into the third tube 1 ml of a 1 A sodium hydroxide solution and 1 ml of a 1 A manganese sulphate solution. Comment on your observations. Write the equations of the reactions. 

Preparation of Sodium Bicarbonate. Saturate 50 ml of a 10% ammonia solution with sodium chloride in the cold. Filter the solution, pour it into a flask, and close it partly with a cork stopper accommodating a gas-discharge tube almost reaching the bottom of the flask. Pass carbon dioxide (from a cylinder or a Kipp gas generator) into the solution until a precipitate stops separating (during 1-1.5 hours). Separate the crystals on a Buchner funnel, wash them with ethanol, and dry them at room temperature in the air. Write the equations of the reactions. What impurities does the product contain ... 

Preparation of Titanium(IIl) Sulphate Solution- Pour 7-10 ml of an acidihed titanyl sulphate solution into a test tube, add 3-5 ml of a 10% sulphuric acid solution, and put in two or three small pieces of zinc. How does the colour of the solution change Write the equation of the reaction. 

Assemble an apparatus for preparing acetylene (see Fig. 54). Put about 5 g of calcium carbide into 25-ml round-bottomed flask 1. Fill dropping funnel 2 and cylinder 3 with a 25% sodium chloride solution. Pour a little of a 1-2% sodium hydroxide solution into wash bottle 4, and a 2% potassium dichromate solution acidified with a dilute sulphuric acid solution into test tube 5. By adding the sodium chloride solution in small portions to the calcium carbide, achieve a uniform stream of gas. When the apparatus is filled with pure acetylene, test the gas for the absence of air in it. How can this be done ... 

Roast 2-3 g of lead carbonate at 450-500 °C in a porcelain bowl. When decomposition of the salt terminates, roast the substance at the same temperature for another two or three hours. Next transfer the product into a beaker and boil it several times with a lead acetate solution. Pour off the solution from the precipitate, filter off the latter, wash it with hot water, and dry it in a drying cabinet at... 

A MiXTbire of 12 g. (0.50 gram atom) of magnesium turnings, 130 g. (1.0 mole) of ethyl acetoacetate, 200 g. of benzene (dried over sodium), and 120 g. (1.50 moles) of acetyl chloride is heated under reflux for two hours in a i-l. round-bottomed flask provided with a condenser closed by a calcium chloride tube and supported in an oil bath (85-90°) (Note 1). The yellow reaction mixture is cooled in an ice bath, and the liquid portion decanted into a separatory funnel. The residue in the flask is washed twice with 50-cc. portions of ether, and the ethereal solution poured over ice. The ether-water mixture is then added to the benzene solution in the separatory funnel, and the mixture is shaken thoroughly (Note 2) the aqueous layer is drawn off and discarded. The benzene-ether solution is washed once with 500 cc. of 5 per cent sodium bicarbonate solution, once with 50 cc. of water, and finally dried over calcium chloride. The ether and most of the benzene are removed by distillation from a water bath, and the remainder of the benzene is driven off at 50°/5o mm. The ethyl diacetylacetate is then precipitated from the residue as copper derivative by the addition of 1200 cc. of a saturated aqueous solution of copper acetate (Note 3). After addition of the copper acetate solution, the contents of the flask are shaken vigorously now and then and allowed to stand for an hour to ensure complete precipitation of the copper derivative. The blue copper derivative is filtered on a Buchner funnel, washed with two 50-cc. portions of water, and transferred directly to a separatory funnel where it is mixed with 600 cc. of ether. 

During the shaking 350 cc. of glacial acetic acid is heated to boiling in a 600-cc. beaker under a hood, and 5 cc. of a saturated sodium chloride solution and 4 cc. of concentrated hydrochloric acid are added. The flame is extinguished, and the filtered hemin solution poured in a steady stream with stirring into the hot mixture the suction flask is rinsed with 15 cc. of chloroform. After the mixture has stood for twelve hours, the crystals are filtered with suction on a small Buchner funnel and washed with 50 cc. of 50 per cent aqueous acetic acid, 100 cc. of distilled water, 25 cc. of alcohol, and 25 cc. of ether. Suction is continued... 

INTO SECOND HALF OF SOLUTION, POUR SOLUTION OF 4 g SODIUM CARBONATE IN 10 ml WATER. WHITE PRECIPITATE IS MnCOj. 

Peel the fruit, weigh to the nearest 0.1 g, and cut a sample of 25 to 50 g from the edible portion. Weigh the sample to the nearest 0.1 g. Slice the sample into many small pieces, transfer to a mortar, and grind with 25 mL of the metaphosphoric acid solution. Pour the liquid from the extract into a 100-mL volumetric flask. Grind the solid residue in the mortar twice using 25 mL of the metaphosphoric acid solution. Add the liquid extract each time to the 100-mL volumetric flask. Add metaphosphoric acid solution to the volumetric flask to a total volume of 100 mL. Filter the solution through a rapid flow, fluted filter paper. Transfer 10.0 mL of the filtrate into a 50-mL Erlenmeyer flask. Titrate rapidly with the DCIP solution. Repeat the titration on two more 10.0-mL samples of the filtrate. Titrate 10.0 mL of metaphosphoric acid solution as a blank. 

Add 30 pL TEMED to 10 mL of gel solution, pour this solution between the plates to fill the gap completely, and insert the comb in the top of the mold (there is no stacking gel with this system) Leave for 10 min for gel to polymerize... 

Exercise 18-28 Explain why the base-induced hydrolysis of methyl 2,4,6-trimethyl-benzoate is unusually slow. Write a mechanism for the hydrolysis of methyl 2,4,6-trimethyl benzoate that occurs when the ester is dissolved in concentrated sulfuric acid and the solution poured into a mixture of ice and water (see Section 18-3A) ... 

All these remedies should he heft on a special shelf in the laboratory. Sodium Residues.—These should not he dropped into the sink or waste box, but should be added in small portions to alcohol, and, when all action has ceased, the solution poured into the sink. 

Reagents, (a) 150 grams of ammonium molybdate are dissolved in a litre of cold water and the solution poured into a litre of nitric acid of sp. gr. i-2. 

Reagent. 40 grams of powdered ammonium molybdate are dissolved in a mixture of 320 c.c. of water and 80 c.c. of 20% ammonia (D 0-925) and the solution poured into a cold mixture of 480 c.c. of 30% nitric acid (D 1-18) and 170 c.c. of water. The reagent should be left at rest for some days in the dark before use. 

Slowly pour the water solution into the carbon tetrachloride solution. Pour it along the side of the larger beaker. 

Diplionylamine (1 part) is mixed with chloroform (1 part), zinc chlorido (1 part), and ziuc oxide (i a part). The mixture is placed in a sealed tube and heated to 200°—210° for seven to eight hours. The mixture is then digested with cono. hydrochloric acid and the filtered solution poured into water to precipitate any unchanged diphenylamine, the hydrochloride of which is dissociated by water. From the... 

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