Potassium solid solution

Iodine is a dark-coloured solid which has a glittering crystalline appearance. It is easily sublimed to form a bluish vapour in vacuo. but in air, the vapour is brownish-violet. Since it has a small vapour pressure at ordinary temperatures, iodine slowly sublimes if left in an open vessel for the same reason, iodine is best weighed in a stoppered bottle containing some potassium iodide solution, in which the iodine dissolves to form potassium tri-iodide. The vapour of iodine is composed of I2 molecules up to about 1000 K above this temperature, dissociation into iodine atoms becomes appreciable. 

Recovery of the wopropyl alcohol. It is not usually economical to recover the isopropyl alcohol because of its lo v cost. However, if the alcohol is to be recovered, great care must be exercised particularly if it has been allowed to stand for several days peroxides are readily formed in the impure acetone - isopropyl alcohol mixtures. Test first for peroxides by adding 0-6 ml. of the isopropyl alcohol to 1 ml. of 10 per cent, potassium iodide solution acidified with 0-6 ml. of dilute (1 5) hydrochloric acid and mixed with a few drops of starch solution if a blue (or blue-black) coloration appears in one minute, the test is positive. One convenient method of removing the peroxides is to reflux each one litre of recovered isopropyl alcohol with 10-15 g. of solid stannous chloride for half an hour. Test for peroxides with a portion of the cooled solution if iodine is liberated, add further 5 g. portions of stannous chloride followed by refluxing for half-hour periods until the test is negative. Then add about 200 g. of quicklime, reflux for 4 hours, and distil (Fig. II, 47, 2) discard the first portion of the distillate until the test for acetone is negative (Crotyl Alcohol, Note 1). Peroxides generally redevelop in tliis purified isopropyl alcohol in several days. 

The oxaziridine ring itself is stable towards alkali there is, for instance, no substitutive ring opening by hydroxyl ions as in oxiranes. 2-r-Butyl-3-phenyloxaziridine (56) is not attacked by methoxide ion in methanol during 12 h at room temperature 3-isopropyl-2-r-octyloxaziridine does not react at room temperature with either solid potassium hydroxide or potassium methoxide solution (57JA5739). 

If the entire amount of alcoholic potassium hydroxide solution is added at this point, there is precipitated a colorless solid, which does not dissolve even on prolonged heating. 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

Acetylene and Potassium in Liquid Ammonia Potassium (40 g) is dissolved in 1 liter of dry liquid ammonia. Dry acetylene is then bubbled into the solution until the blue color is discharged. A solution of 15 g of estrone in 300 ml of dioxane is prepared and diluted with 300 ml of ether, cooled, and added to the potassium acetylide solution over a period of 10 min. The liquid ammonia is allowed to evaporate, an additional 500 ml of ether is added, and the mixture is allowed to stand overnight. About 3 liters of 5 % sulfuric acid is added and the organic layer separated. The water layer is re-extracted with fresh ether, and the combined ether extracts are washed twice with 5 % sodium carbonate solution, th6n several times with water, and finally evaporated under reduced pressure. The residue is dissolved in 150 ml of methanol, then an equal quantity of hot water is added and the mixture cooled. The precipitated solid is collected, washed with cold 60 % methanol and crystallized once from methanol-water to give 14.8 g (85%) of 17a-ethynylestradiol mp 143-144°. 

A mixture of 17 g of the methiodide and 32 ml of a 40 % aqueous potassium hydroxide solution is heated with stirring in a flask fitted with a condenser. The heating bath should be kept at 125-130°, and the heating should be continued for 5 hours. The cooled reaction mixture is then diluted with 30 ml of water and washed twice with 25-ml portions of ether. The aqueous layer is cautiously acidified in the cold with concentrated hydrochloric acid to a pH of about 2 and then extracted five times with 25-ml portions of ether. The combined extracts are washed twice with 10% sodium thiosulfate solution and are dried (magnesium sulfate). Removal of the solvent followed by distillation affords about 3 g of 4-cyclooctene-l-carboxylic acid, bp 125-12671-1 mm. The product may solidify and may be recrystallized by dissolution in a minimum amount of pentane followed by cooling in a Dry-Ice bath. After rapid filtration, the collected solid has mp 34-35°. 

A 500-ml three-necked flask is fitted with a mechanical stirrer, a thermometer, a gas outlet, and a gas inlet tube dipping into the solution. The flask is charged with a solution of cyanuric acid (15 g, 0.116 mole) dissolved in 300 ml of 5% aqueous potassium hydroxide solution. The flask is cooled in an ice-salt bath with stirring to 0° and irradiated with a mercury lamp. A rapid stream of chlorine is passed into the flask (approx. 5 ml/sec), whereupon a heavy white precipitate forms. The addition of gas is continued until the solid material no longer forms (approx. 2 hours). The flask is briefly flushed with air, the product is collected by suction filtration in an ice-cooled funnel, and the residue washed with several small portions of cold water. Since it undergoes slow hydrolysis, the product should be dried in a vacuum oven. The crude product has a variable melting point (195-225°) the yield is about 20 g (approx. 75%). 

It is dissolved in hot methanol and heated on the steam bath with 10% methanolic potassium hydroxide solution (15.8 ml) for 10 minutes. Then more potassium hydroxide solution (2 ml) is added, the solution is cooled and on dilution with water a solid (II), MP 245° to 255°C, is obtained. A second crop is obtained from the mother liquors. Several recrystalli2ations from acetone yield an analytical sample, MP 262° to 265°C, [oIq is -2.1°. 

Determination of calcium. Pipette two 25.0 mL portions of the mixed calcium and magnesium ion solution (not more than 0.01M with respect to either ion) into two separate 250 mL conical flasks and dilute each with about 25 mL of de-ionised water. To the first flask add 4 mL 8 M potassium hydroxide solution (a precipitate of magnesium hydroxide may be noted here), and allow to stand for 3-5 minutes with occasional swirling. Add about 30 mg each of potassium cyanide (Caution poison) and hydroxylammonium chloride and swirl the contents of the flask until the solids dissolve. Add about 50 mg of the HHSNNA indicator mixture and titrate with 0.01 M EDTA until the colour changes from red to blue. Run into the second flask from a burette a volume of EDTA solution equal to that required to reach the end point less 1 mL. Now add 4 mL of the potassium hydroxide solution, mix well and complete the titration as with the first sample record the exact volume of EDTA solution used. Perform a blank titration, replacing the sample with de-ionised water. 

This reaction is slow in acid solution, but it is very rapid in neutral solution. For these reasons, potassium permanganate solution is rarely made up by dissolving weighed amounts of the purified solid in water it is more usual to... 

Procedure A. Prepare an approximately 0.1 JVf solution of ammonium iron(II) sulphate by dissolving about 9.8 g of the solid in 200 mL of sulphuric acid (0.5M) in a 250 mL graduated flask, and then making up to the mark with freshly boiled and cooled distilled water. Standardise the solution by titrating 25 mL portions with standard potassium permanganate solution (0.02M) after the addition of 25 mL sulphuric acid (0.5JVf). 

PI. Saturated potassium hydrogentartrate solution. The pH is insensitive to changes of concentration and the temperature of saturation may vary from 22 to 28 °C the excess of solid must be removed. The solution does not keep for more than a few days unless a preservative (crystal of thymol) is added. 

Prepare 250 mL of 0.02 M potassium dichromate solution and an equal volume of ca 0.1 M ammonium iron(II) sulphate solution the latter must contain sufficient dilute sulphuric acid to produce a clear solution, and the exact weight of ammonium iron(II) sulphate employed should be noted. Place 25 mL of the ammonium iron(II) sulphate solution in the beaker, add 25 mL of ca 2.5M sulphuric acid and 50 mL of water. Charge the burette with the 0.02 M potassium dichromate solution, and add a capillary extension tube. Use a bright platinum electrode as indicator electrode and an S.C.E. reference electrode. Set the stirrer in motion. Proceed with the titration as directed in Experiment 1. After each addition of the dichromate solution measure the e.m.f. of the cell. Determine the end point (1) from the potential-volume curve and (2) by the derivative method. Calculate the molarity of the ammonium iron(II) sulphate solution, and compare this with the value calculated from the actual weight of solid employed in preparing the solution. 

Standard 0.002M potassium bromate solution. From the pure solid. 

Reagents.f Potassium iodide solution. Dissolve 15 g of solid in 100 mL water. 

Potassium hydroxide solution. Prepare a 0.4M potassium hydroxide solution by dissolving solid potassium hydroxide (preferably calcium-free) in de-ionised water and make up to I L in a graduated flask. 

Reference has already been made to the dehydration of alums (Sect. 1.2 and Table 10), decomposition of ammonium metal phosphates (Sect. 4.1.5) and the use of KMn04—KCIO4 solid solutions in mechanistic studies of the decomposition of potassium permanganate (Sect. 3.6). 

C. 4-Amino-l-tert-butyloxycarbonylpiperidine-4-carboxylic acid (3). A 2000-mL, round-bottomed flask equipped with a magnetic stirbar is charged with a suspension of the hydantoin 2 (40.0 g, 0.8 mol) in 340 mL of THF (Note 12), and 340 mL of 2.0M potassium hydroxide solution (Note 13) is added in one portion. The flask is stoppered and the reaction mixture is stirred for 4 hr (Note 14) and then poured into a 1000-mL separatory funnel. The layers are allowed to separate over 45 min and the aqueous layer is then drained into a 1000-mL round-bottomed flask. This solution is cooled at 0°C while the pH is adjusted to 8.0 by the slow addition of ca. 100 mL of 6.0N HC1 solution. The resulting solution is further acidified to pH 6.5 by slow addition of 2.0 N HC1 solution (Note 15). The white precipitate which appears is collected by filtration on a Buchner funnel and the filtrate is concentrated to a volume of 60 mL to furnish additional precipitate which is collected by filtration. The combined portions of white solid are dried at room temperature under reduced pressure (65°C 0.5 mm) for 12 hr and then suspended in 100 mL of chloroform (Note 16) and stirred for 45 min. The white solid is filtered and then dried under reduced pressure (85°C 0.5 mm) for 24 hr to yield 13.4-14.1 g (64-68%) (Note 17) of the amino acid 3 as a white solid (Note 18). 

The hydrolytic depolymerisation of PETP in stirred potassium hydroxide solution was investigated. It was found that the depolymerisation reaction rate in a KOH solution was much more rapid than that in a neutral water solution. The correlation between the yield of product and the conversion of PETP showed that the main alkaline hydrolysis of PETP linkages was through a mechanism of chain-end scission. The result of kinetic analysis showed that the reaction rate was first order with respect to the concentration of KOH and to the concentration of PETP solids, respectively. This indicated that the ester linkages in PETP were hydrolysed sequentially. The activation energy for the depolymerisation of solid PETP in a KOH solution was 69 kJ/mol and the Arrhenius constant was 419 L/min/sq cm. 21 refs. 

Primary aromatic amides are crystalline solids with definite melting points. Upon boiling with 10-20 per cent, sodium or potassium hydroxide solution, they are hydrolysed with the evolution of ammonia (vapour turns red litmus paper blue and mercurous nitrate paper black) and the formation of the alkali metal salt of the acid ... 

Sometimes it so happens that crystals of a new salt are formed when solutions of two simple salts are mixed and the mixed solution is evaporated. The salt thus obtained is a distinct chemical substance in the solid state as well as in solution. In aqueous solution, it does not dissociate into all the simple ions of the salts it is obtained from, but yields complex ions along with the simple ions. Such a salt is known as a complex salt. A characteristic feature of complex salts is that in these the constituents retain their separate entities both in the solid state and in solution. Potassium ferrocynide, K4Fe(CN)6, is a complex salt and is obtained on mixing the solution of a ferrous salt with an excess of potassium cyanide solution. From its composition [Fe(CN)2,4 KCN], it appears to be a mixture of ferrous cyanide and potassium cyanide in the ratio of 1 4, and is thus taken to be an ordinary double salt. This representation of the compound is, however, not satisfactory since it responds neither to tests for Fe2+ ions nor to those for CN ions but does respond to tests for K+ ions and tetravalent Fe(CN)Jj ions. The ionization reaction of the complex salt cited in the present example can be represented as ... 

As we can see from the last entry in this table, we have deduced only a rule. In InBi there are Bi-Bi contacts and it has metallic properties. Further examples that do not fulfill the rule are LiPb (Pb atoms surrounded only by Li) and K8Ge46. In the latter, all Ge atoms have four covalent bonds they form a wide-meshed framework that encloses the K+ ions (Fig. 16.26, p. 188) the electrons donated by the potassium atoms are not taken over by the germanium, and instead they form a band. In a way, this is a kind of a solid solution, with germanium as solvent for K+ and solvated electrons. K8Ge46 has metallic properties. In the sense of the 8-A rule the metallic electrons can be captured in K8Ga8Ge38, which has the same structure, all the electrons of the potassium are required for the framework, and it is a semiconductor. In spite of the exceptions, the concept has turned out to be very fruitful, especially in the context of understanding the Zintl phases. 

B. 3-Methylcoumarilic acid. Ethyl 3-methylcoumarilate (70 g.) and 500 ml. of 10% aqueous potassium hydroxide solution are refluxed for 1 hour. The clear yellowish solution is acidified while hot (Note 5) with a slight excess of concentrated hydrochloric acid to precipitate the 3-methylcoumarilic acid. The suspension is cooled to room temperature, and the colorless solid is filtered with suction. The filter cake is resuspended in 500 ml. 

During ozonolysis of vinyl fluoride an explosive solid residue is produced, and the volatile ozonide, trapped at —63°C, may explode spontaneously or dining removal by syringe [1]. During the cryogenic distillation of the ozonide (formulated as a trioxolane), several explosions occurred, and the explosive reaction residue was destroyed by digestion with 5% potassium iodide solution for 24 h [2],... 

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