Potassium, powdered

The methyl ethers of many aryl carbinols cleave in Et20 with liq Na-K alloy or with potassium powder (reaction of the latter is facilitated with the aid of small-edged pieces of quartz glass to cut through incrustations on the potassium on shaking), e.g. ... 

CHLOROMETHANE (74-87-3) CH3CI Highly flammable gas [explosion limits in air (vol %) 8.1 to 17.2 flashpoint <32°F/<0°C autoignition temp 1170°F/632°C Fire Rating 4]. Moisture causes decomposition. Violent reaction with strong oxidizers, acetylene, anhydrous aluminum trichloride, ammonia, amines, ethylene, fluorine, interhalogens magnesium, potassium, powdered aluminum or zinc, sodium, and... 

DICHLOROETHANE or 1,1-DICHLOROETHANE (75-34-3) C2H4CI2 Forms explosive mixture with air [explosion limits in air (vol %) 5.6 to 11.4 flash point 10°F/-12°C autoignition temp 856°F/458°C Fire Rating 3]. Violent reaction with strong oxidizers, potassium powdered metals alkaline earth (barium, calcium, strontium sometime magnesium is included) and alkali metals (lifliium, sodium. 

For Fittig syntheses the halide and the diluent must be quite rigidly dried. The sodium is used as wire or slices but, when reaction is sluggish, it is best to use sodium or potassium powder. A 0.05-molar excess of the metal is preferable. 

CHEMICAL PROPERTIES Attacks chemically active metals such as potassium, powdered aluminum, zinc and magnesium reacts with water to form hydrochloric acid AT... 

CHEMICAL PROPERTIES stable under ordinary conditions of use and storage hazardous polymerization will not occur can react vigorously with chemically-active metals, such as sodium, calcium, potassium, powdered aluminum, magnesium and zinc FP (not applicable) LFL/UFL (not applicable) AT (not applicable). 

CHEMICAL PROPERTIES bums with a smoky flame reacts with chemically-active metals such as potassium, powdered aluminum, zinc, and magnesium reacts with water to form hydrochloric acid FP (< 0 C, < 32 F) LFL/UFL (8.1%, 17.4%) AT (632°C, 1170°F) HF (-81.9 kJ/mol gas at 25 C). 

METHYL CHLORIDE CH,Ct ChtwOTiMhane Cbemkany active imtab potassium, powdered aluminum, zinc, magnesium NA 7.6 19... 

CH2CI-CO-CH3. Colourless lachrymatory liquid b.p. 119°C. Manufactured by treating propanone with bleaching powder or chlorine. It is used as a tear gas and is usually mixed with the more potent bromoacetone. chloro acids Complex chloroanions are formed by most elements of the periodic table by solution of oxides or chlorides in concentrated hydrochloric acid. Potassium salts are precipitated from solution when potassium chloride is added to a solution of the chloro acid, the free acids are generally unstable. 

B) FROM i,2-DIBROI IOETH. NE. Required Powdered potassium hydroxide, 25 g. rectified spirit, 100 ml. ethylene dibromide, 15 ml. (33 g.). 

Add 5 g. of potassium hydrogen tartrate and 5 g. of antimony trioxide (each being finely powdered) to 30 ml. of water contained in a small flask, and boil the mixture under a reflux water-condenser for 15 minutes. Then filter hot, using a Buchner funnel and flask which have been preheated by the filtration of some boiling distilled water. Pour the clear filtrate into a beaker and allow to cool. Potassium antimonyl tartrate separates as colourless crystals. Filter, drain and dry. Yield, 5 g. The product can be recrystallised from hot water, but this is usually not necessary. 

The crude acetonitrile contains as impurity chiefly acetic acid, arising from the action of phosphoric acid on the acetamide. Therefore add to the nitrile about half its volume of water, and then add powdered dry potassium carbonate until the well-shaken mixture is saturated. The potassium carbonate neutralises any acetic acid present, and at the same time salts out the otherwise water-soluble nitrile as a separate upper layer. Allow to stand for 20 minutes with further occasional shaking. Now decant the mixed liquids into a separating-funnel, run off the lower carbonate layer as completely as possible, and then pour off the acetonitrile into a 25 ml, distilling-flask into which about 3-4 g. of phosphorus pentoxide have been placed immediately before. Fit a thermometer and water-condenser to the flask and distil the acetonitrile slowly, collecting the fraction of b.p. 79-82°. Yield 9 5 g. (12 ml.). 

Then, while the diazonium solution is standing in ice-water, dissolve 55 g. of powdered copper sulphate (CuS04,5Ha0) in 200 ml. of water contained in a 1500 ml. flat-bottomed flask, for which a steam-distillation fitting is available for subsequent use. Place a thermometer in the copper sulphate solution and warm the latter to 60-65 . Now cautiously add a solution of 60 g. of powdered potassium cyanide in too ml. of water to the copper... 

Now transfer the cold distillate to a separating-funnel, and shake vigorously with about 50-60 ml. of ether run oflF the lower aqueous layer and then decantf the ethereal solution through the mouth of the funnel into a 200 ml. conical flask. Replace the aqueous layer in the funnel, and extract similarly twice more with ether, combining the ethereal extracts in the conical flask. Add 3-4 g. of dry powdered potassium carbonate to the ethereal solution, securely cork the flask and shake the contents gently. The ethereal solution of the phenol... 

A) Extract the mixture with about 40 ml. of chloroform, in which the free base is very soluble. Run off the lower chloroform layer, dry it with potassium carbonate as in (a), and then add carbon tetrachloride slowly with stirring to the filtered chloroform solution until the base starts to crystallise out. Allow to stand for a short time (t.e., until the deposition of crystals ceases) and then filter at the pump as the crystals lose the last trace of solvent, they tend as before to break up into a fine powder, the deep green colour becoming paler in consequence. 

Required Aniline, 30 ml. onrhlorobenzoic acid, 8 g. potassium carbonate, 8 g. powdered copper oxide, 0 4 g. 

Add 5 g. of powdered potassium cyanide to a mixture of 20 ml. of water and 50 ml. of ethanol contained in a 200 ml. conical flask, and then add 25 mi. (26 g.) of freshly distilled benzaldehyde. Fit the flask with a reflux water-condenser, and boil the mixture gently on a water-bath for 30 minutes, a clear solution being rapidly obtained. Then pour the solution into a beaker and cool the benzoin separates as a crystalline mass... 

Transfer the quinoline chlorozincate to a beaker, add a small quantity of water, and then add 10% sodium hydroxide solution until the initial precipitate of zinc hydroxide completely redissolves, and the free quinoline separates. Transfer the mixture to a separating-funnel, wash out the beaker with ether, adding the washings also to the solution in the funnel, and then extract the quinoline twice with ether. Dry the united ethereal extracts by adding an ample quantity of powdered potassium hydroxide and... 

Digestion. 20-25 mg. of the substance whose nitrogen content is to be estimated are weighed out in a stoppered weighing-tube and then transferred to the flask L that has been previously dried in an oven at izo C. With care, the substance may be transferred directly into the bulb of the flask without any adhering to the sides. If any material sticks on the way down, the flask should be tapped gently to cause the substance to fall to the bottom. 2 G. of the catalyst mixture (32 g. of potassium sulphate, 5 g. of mercury sulphate and ig. of selenium powder, well mixed) are added and 3 ml. of A.R. cone, sulphuric acid are measured out carefully and poured into the digestion... 

In preparing this mixture, the lactose and the potassium nitrate should be powdered separately and then mixed solely by shying. They should not be ground together in a mortar. 

Potassium Hydroxide, Alcoholic. Boil under reflux a mixture of 10 g. of powdered KOH and 100 ml. of rectified spirit for 30 minutes. Cool and if solid material remains, decant through a filter of glass-wool. 

Iodine Solution. Cold saturated aqueous solution. (If a more concentrated solution is required, add i g. of powdered iodine to a solution of 2 g. of potassium iodide in a minimum of water, and dilute the solution to 100 ml.)... 

Grind finely pure laboratory grade, anhydrous potassium fluoride, and heat it in an electrically heated oven at 180-210° store in a desiccator. Before use, dry the powdered salt at 180° for 3 hours and grind again in a warm (ca. 50°) glass mortar. 

Mix 200 g. of adipic acid intimately with 10 g. of finely-powdered, crystallised barium hydroxide. Place the mixture in a 1-litre distilling flask, fitted with a thermometer reaching to within 5 mm. of the bottom connect the flask with a condenser and receiver. Heat the mixture gradually in an air bath (1) to 285-295° during about 90 minutes and maintain it at this temperature mitil only a small amount of dry residue remains in the flask this requires a further 2 hours. The temperature must not be allowed to rise above 300°, since at this temperature the adipic acid distils quite rapidly the best working temperature is 290°. The cycZopentanone distils slowly accompanied by a little adipic acid. Separate the ketone from the water in the distillate, and dry it with anhydrous potassium carbonate this treatment simultaneously removes the traces of adipic acid present. Finally distil from a flask of suitable size and collect the cycZopentanone at 128-131°. The yield is 92 g. 

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