Potassium carbonate vapors

Studies regarding the reactions between sodium carbonate and potassium carbonate vapors and refractories have been limited in scope. (Many studies conducted by industry may not have been reported in the literature.) The majority have involved the examination of the degenerated features of refractories after an average service campaign. Most of the articles published have concerned the reactions between alkalies and alumino-silicate refractories utilized in glass melting and blast furnaces. 

Vapor phase pyrolysis of 2-aminobiphenyl in chloroform at 350°C produces carbazole,as does heating at 500-800°C in a high-frequency glow discharge at 25-34 A small amount (11%) of carbazole 280 was formed during the reaction of 281 with copper-potassium carbonate and 1-iodo-naphthalene in nitrobenzene. ... 

Oxadiazoles of low molecular weight are volatile liquids. The aliphatic derivatives possess a strong ethereal odor, while the aromatic ones remind of aromatic esters. Oxadiazole itself is a liquid boiling at 87°, soluble in water and aU organic solvents. It cannot be recovered from its solutions by distillation because it distils with the vapor of the solvent, even in ethereal solution. It can, however, be isolated as an oil from its aqueous solution by salting out with potassium carbonate, calcium chloride, or ammonium sulfate 55 c). 

Substances that are ordinarily deliquescent are sulfuric add (concentrated), glycerol, calcium chloride crystals, sodium hydroxide (solid), and 100% ethyl alcohol. In an enclosed space, these substances deplete the water vapor present to a definite degree. Other substances are used to accomplish this end by chemical reaction, e.g.. phosphorus pentoxide (forming phosphoric acid), and boron trioxide (forming boric acid). Water is absorbed from nonmiscible liquids by addition of such substances as anhydrous sodium sulfate, potassium carbonate, anhydrous calcium chloride. and solid sodium hydroxide. The converse phenomenon is known as efflorescence. 

A solution of 690 g. (5.0 moles) of potassium carbonate in 2 1. of distilled water is prepared in a 4-1. polyethylene beaker or pail, and 500 g. of crushed ice and 300 ml. of ether are added. The cold reaction mixture is cautiously added to the carbonate solution with stirring. The pH of the aqueous layer becomes about 9. The ether layer is separated, and the aqueous layer is extracted with three 200-ml. portions of ether. The ether solutions are combined and washed with three 100-ml. portions of water. The ether solution is dried over anhydrous sodium sulfate, and the ether is removed by distillation. The oily residue is fractionated through a 15-cm. Vigreux column under reduced pressure. There is a fore-run of about 0.5 ml., and then 59-75 g. (60-77%) of l-bromo-2-fluoroheptane is collected at 70-78° (15 mm.) 25d 1.4408-1.4420. According to vapor phase chromatography, it is about 90% pure (Note 5). 

The flask A is heated by means of an oil bath maintained at 120-125° (Note 1) the mixed vapors of alcohol and water, passing through the fractionating column, are condensed in D and the moist alcohol is delivered under the surface of the alcohol contained in flask B. In flask B are placed 250 cc. of absolute alcohol and about 200 g. of freshly ignited potassium carbonate. Flask B is heated in an oil bath maintained at about 95-100°. The moist alcohol delivered to the flask B is dried by the potassium carbonate and subsequently returned as vapor under the surface of the liquid in flask A. The tube C, which is open to the air, acts as a safety valve to the otherwise closed system. 

The following table provides data on the common salts used for salting out in chromatographic headspace analysis, as applied to direct injection methods and to solid phase microextraction.1 2 Data are provided for the most commonly available salts, although others are possible. Sodium citrate, for example, occurs as the dihydrate and the pentahydrate. The pentahydrate is not as stable as the dihydrate, however, and dries out on exposure to air, forming cakes. Potassium carbonate occurs as the dihydrate, trihydrate, and sesquihydrate however, data are provided only for the anhydrous material. The solubility is provided as the number of grams that can dissolve in 100 ml of water at the indicated temperature. The vapor enhancement cited is the degree of increase of the concentration of vapor over the solution of a 2% (mass/mass) ethanol solution in water at 60°C.3... 

A. When sufficiently heated, a sample chars and emits flammable vapors having an odor resembling that of burning sugar. At a higher temperature and with free access to air, the heat consumes the carbon of the black residue, and a white, fused mass of potassium carbonate remains that imparts a red-purple color to a nonluminous flame. 

Deliquescence is a property of substances very soluble in water. When such substances, potassium carbonate or calcium chloride for example, are exposed to the air, the water vapor forms with the substance a small quantity of a saturated solution. This saturated solution has a lower vapor pressure than that of the atmosphere, that is, the water is held by the substance, it does not tend to escape, hence more water vapor is added from the air, and finally the substance is entirely dissolved in this condensed vapor. Common salt or sodium chloride often appears to deliquesce, but the deliquescence is due to the very soluble magnesium and calcium chlorides which are usually mixed with commercial sodium chloride. Sodium nitrate is very soluble in water at the ordinary temperature, but potassium nitrate is only slightly soluble. Hence potassium nitrate, and not sodium nitrate, is used in the manufacture of gunpowder. 

Silica gel OF 264 thin layer plate has been used with developing solvent of methanol - chloroform (1 3 ) to detect lincomycin (26). Lincomycin has an Rf of 0.65 detected by charring, iodine vapors, or permanganate spray. The latter consists of 10 gm of potassium carbonate, 8 gm of sodium periodate, and 1 gm of potassium permanganate in 500 ml of water. The mixture was left standing for 16 hours and filtered. 

Aqueous alcohol is distilled from a mixture of anhydrous oxalic acid (180 g) and ethanol (500 ml), through a short column, into a second flask containing roasted potassium carbonate (200 g) under ethanol (250 ml). This second flask is heated just to the boiling point of alcohol and is connected to the reaction flask by a slightly inclined tube so that the vapor of the dehydrated alcohol passes back into the reaction mixture. After 5 hours heating diethyl oxalate is thus obtained in 80-90% yield. 

Hot potassium carbonate is usually used as the absorption solvent for carbon dioxide removal. A small purge stream is vented from the suction side of the compressor to remove inerts before the gas enters the carbon dioxide absorber. Carbon dioxide is vented to the atmosphere and the ethylene-rich offgas from the absorber is recycled to the acetic acid vaporizer. 

Carbon dioxide (CO2) 11.2 Nitrogen (N2) 4.2 Carbon monoxide (CO) 1.1 Water vapor (HjO) 1.1 Hydrogen sulfide (H2S) 0.1 Methane (CH4 0.1 Hydrogen (Hj) 34.1 Potassium carbonate (KjCOj) 8.4 Potassium suifate (K2SO4) 8.1 Potassium suifide (KjS) 4.9 Suifur(S) 0.2 Potassium nitrate (KNOj) 0.1 Potassium thiocyanate (KSCN) 0.1 Ammonium carbonate ((NH4)2CO ) 0.1 Carbon (C)... 

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