Potassium Acetate Solution Chloride

Chlorides. — Dilute 5 cc. of potassium acetate solution with 20 cc. of water, and add 5 cc. of nitric acid followed by silver nitrate solution. At most a slight opalescent turbidity should develop. 

Quantitative (total tartaric acid). 100 c.c. of the vinegar are treated in a beaker with 1 c.c. of 20% potassium acetate solution and 15 grams of powdered potassium chloride. When the latter has dissolved, 20 c.c. of 95% alcohol are added, the subsequent procedure being as indicated for the determination of the total tartaric acid in wine q.v., p. 193). 

To conduct a water sorption study, the product was stored in desiccators with solid salt or saturated salt solutions for 48 h of equilibration at an ambient temperature (Figure 8). The salts included phosphorus pentoxide, lithium chloride, potassium acetate, magnesium chloride, potassium carbonate, and sodium chloride, which generated relative humidities of, approximately, 0, 11, 23, 33, 43, and 75%, respectively. The vials were sealed immediately after equilibration. The moisture in the lyophilized product was determined by the Karl Fischer method. 

Alternatively, use the following procedure in which triethylamine replaces potassium acetate as the basic catalyst. Place 2 1 g. (2-0 ml.) of purified benzaldehyde, 2 0 ml. of anhydrous triethylamine and 5 0 ml. of A.R. acetic anhydride in a 200 ml. round-bottomed flask, equipped with a short reflux condenser and a calcium chloride drying tube. Boil the solution gently for 24 hours—heating may be interrupted. Incorporate a steam distillation apparatus in the flask and steam distil until the distillate is no longer cloudy (about 100 ml.) and then collect a further 50 ml. of the distillate di ard the steam distillate. Transfer the residue in the flask to a 400 ml. beaker, add water until the vplume is about 200 ml., then 0 2 g. of decolourising carbon, and boil for a few minutes. Filter the hot solution, and acidify the hot filtrate with 1 1 hydrochlorioiaoid... 

Complexing agents, which act as buffers to help control the pH and maintain control over the free metal—salt ions available to the solution and hence the ion concentration, include citric acid, sodium citrate, and sodium acetate potassium tartrate ammonium chloride. Stabilizers, which act as catalytic inhibitors that retard the spontaneous decomposition of the bath, include fluoride compounds thiourea, sodium cyanide, and urea. Stabilizers are typically not present in amounts exceeding 10 ppm. The pH of the bath is adjusted. 

Cellulose dissolved in suitable solvents, however, can be acetylated in a totally homogeneous manner, and several such methods have been suggested. Treatment in dimethyl sulfoxide (DMSO) with paraformaldehyde gives a soluble methylol derivative that reacts with glacial acetic acid, acetic anhydride, or acetyl chloride to form the acetate (63). The maximum degree of substitution obtained by this method is 2.0 some oxidation also occurs. Similarly, cellulose can be acetylated in solution with dimethylacetamide—paraformaldehyde and dimethylformamide-paraformaldehyde with a potassium acetate catalyst (64) to provide an almost quantitative yield of hydroxymethylceUulose acetate. 

In specific applications to phase transfer catalysis, Knbchel and his coworkers compared crown ethers, aminopolyethers, cryptands, octopus molecules ( krakenmole-kiile , see below) and open-chained polyether compounds. They determined yields per unit time for reactions such as that between potassium acetate and benzyl chloride in acetonitrile solution. As expected, the open-chained polyethers were inferior to their cyclic counterparts, although a surprising finding was that certain aminopolyethers were superior to the corresponding crowns. 

The work of Hyatt on cyclotriveratrylene—derived octopus molecules contrasts with this. Of course, these species have the advantage of ligand directionality absent in the benzene-derived octopus molecules. Except for the shortest-armed of the species (i.e., n = 1), all of the complexing agents (i.e., n = 2—4) were capable of complexing alkali metal cations. Synthesis of these species was accomplished as indicated below in Eq. (7.7). These variations of the original octopus molecules were also shown to catalyze the reaction between benzyl chloride and potassium acetate in acetonitrile solution and to effect the Wittig reaction between benzaldehyde and benzyltriphenylphos-phonium chloride. 

To a solution of 6.78 g of 6a-fluoro-9a-bromo-11 (3,17a,21-trihydroxy-16a-methyl-1,4-preg-nadiene-3,20-dione-21 -acetate in 175 ml of acetone was added 6.78 g of potassium acetate and the resulting suspension was heated under reflux for a period of 17 hours. The mixture was then concentrated to approximately 60 ml volume at reduced pressure on the steam bath, diluted with water and extracted with methylene chloride. The methylene chloride extracts were combined, washed with water, dried over anhydrous sodium sulfate and evaporated. 

Filtration of the catalyst over a Hyflo pad and removal of the solvent left a yellow crystalline residue. The crude mixture of ketone and potassium acetate was partitioned between methylene chloride (300 cc) and water (1 liter), The layers were separated and the water layer washed with methylene chloride (3 x 50 cc). The organic layers were combined, washed with 3N sodium hydroxide solution (2 x 50 cc), water (3 x 100 cc), dried over anhydrous sodium sulfate and filtered. The solvent was removed and the product recrystallized from ethanol to give 2-amino-2 -fluorobenzophenone as yellow prisms melting at 126° to 128°C,... 

Perchlorate as potassium perchlorate (ca 400 mg as the sodium salt in 25 mL solution). Warm the solution to 80-90 °C and treat with a slight excess of a cold saturated solution of potassium acetate. Allow to cool and after 1 hour collect the precipitate on a weighed porcelain filtering crucible. Wash twice with 0.05M potassium chloride and then with four 5 mL portions of equal volumes of anhydrous ethyl acetate and anhydrous butan-l-ol. Dry the precipitate at 110°C for 30-60 minutes and then heat at 350 °C in an electric furnace for 15 minutes. Weigh as KC104 (Section 11.68). 

The reaction is a sensitive one, but is subject to a number of interferences. The solution must be free from large amounts of lead, thallium (I), copper, tin, arsenic, antimony, gold, silver, platinum, and palladium, and from elements in sufficient quantity to colour the solution, e.g. nickel. Metals giving insoluble iodides must be absent, or present in amounts not yielding a precipitate. Substances which liberate iodine from potassium iodide interfere, for example iron(III) the latter should be reduced with sulphurous acid and the excess of gas boiled off, or by a 30 per cent solution of hypophosphorous acid. Chloride ion reduces the intensity of the bismuth colour. Separation of bismuth from copper can be effected by extraction of the bismuth as dithizonate by treatment in ammoniacal potassium cyanide solution with a 0.1 per cent solution of dithizone in chloroform if lead is present, shaking of the chloroform solution of lead and bismuth dithizonates with a buffer solution of pH 3.4 results in the lead alone passing into the aqueous phase. The bismuth complex is soluble in a pentan-l-ol-ethyl acetate mixture, and this fact can be utilised for the determination in the presence of coloured ions, such as nickel, cobalt, chromium, and uranium. 

Methyldihydrocodeinone. A solution of bromomethyldihydrocodeinone (18.2 g) in 200 cc of 2 N acetic acid with 5 g of potassium acetate, a small amount of gum aribic, and 10 cc of 1% palladius chloride solution, was hydrogenated (see reductions chapter for instructions to hydrogenate). Remove the catalyst by filtration, make alkaline with NaOH, and extract with small portions of ether until a total of 2 liters is used. Combine the ether extracts, wash thoroughly with dilute alkali, and filter off the 12 g of white crystalline product. Recrystallize with ether or ethyl acetate to get mp of 144-144.5°. 

The checkers prepared a crystalline complex of potassium acetate with isomer B of dicyclohexyl-18-crown-6 polyether by the following procedure. To a stirred solution of 15.0 g. (0.0404 mole) of dicyclohexyl-18-crown-6 polyether (mixture of isomers) in 50 ml. of methanol was added a solution of 5.88 g. (0.0600 mole) of anhydrous potassium acetate (dried at 100° under reduced pressure) in 35 ml. of methanol. The resulting solution was concentrated under reduced pressure with a rotary evaporator, and the residual white solid was extracted with 35 ml. of boiling methylene chloride. The resulting mixture was filtered and the filtrate was cooled in a dry ice-acetone bath and slowly diluted with petroleum ether (b.p. 30-60°, approximately 200 ml. was required) to initiate crystallization. The... 

Potassium Tetranitrito - diammino - cobaltate, [Co(NH3)3 (N02)4]K.—The salt is produced by treating cobaltous chloride with excess of ammonium chloride and potassium nitrite, and warming the liquid to 50° C. It is then allowed to stand at low temperature for several hours, when crystals separate. They are dissolved in boiling water, filtered. and cooled, when lustrous browm rhombic crystals separate. The salt may be obtained from the ammonium salt by treating a warm aqueous solution with potassium acetate. 

In a well-ventilated hood, behind an explosion shield, to a finely divided suspension of 2.6 gm (0.01 mole) of fumardianilide in 90 ml of glacial acetic acid, 30 ml of acetic anhydride, and also containing 8 gm of freshly fused potassium acetate and 2 gm of phosphorus pentoxide, cooled to +7°C is added, slowly, with vigorous stirring, 25 ml of a 20 % solution of nitrosyl chloride (5 gm of nitrosyl chloride, 0.08 mole) in acetic anhydride. After the addition has been completed, stirring is continued for 2 hr while the reaction temperature is maintained between 7° and 12°C. During this period, much of the suspended material dissolves. 

The amine (0.1 mole) is dissolved in a buffered (pH 4-5) solution of 500 ml of 60 % aqueous acetic acid and 68 gm of sodium acetate. The reaction mixture is warmed to 90°C. Then 69 gm (1.0 mole) of sodium nitrite dissolved in 100 ml of water is added dropwise over a 45 min period while heating at 90°C is continued. After the addition, the reaction mixture is heated for 2 hr, cooled, poured into 200 ml of cold water, and extracted three times with 200 ml portions of ether. The ether was washed with 10 % potassium carbonate solution until basic, then with saturated sodium chloride solution, dried, stripped, and distilled to obtain the products shown in the table. 

Acquaint yourself with the appearance of aluminium potassium alum, sodium chloride, and calcium acetate crystals using a microscope. To do this, transfer a drop of the relevant solution containing a few crystals onto a slide. Cover the liquid with a cover glass and place the preparation on the microscope stage. Draw the shape of the crystals. 

Lead Iodide. Add a potassium iodide solution to one of lead acetate. What is observed Pour off a part of the solution with the precipitate (about 1 ml) into a beaker, add 10-15 ml of water acidified with acetic acid, and heat the solution. What is its colour Cool the solution. Explain the observed phenomena. Compare the solubility of lead iodide and chloride in water. How does it change with the temperature ... 

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