Alkali bicarbonates preparation

The alkalized aluminas are prepared by impregnation with solutions of alkali salts, for example, alkali bicarbonates. The salts are typically decomposed by heat-treatment to 500 °C. The alkali oxide contents are typically 5% (wt), but a range of 1-10% has been reported. The surface areas are reduced... 

Saiki, Y., and T. Suzuki, 1966. Anomalies in the infrared spectra of ammonium carbonate and ammonium bicarbonate prepared by alkali halide pellet technique. Japan Analyst 15 608. 

Sodium bicarbonate may be prepared by the ammonia-salt (Solvay) process. Carbon dioxide is passed through a solution of sodium chloride in ammonia water. Sodium bicarbonate is precipitated and the ammonium chloride remains in solution. The ammonium chloride is heated with lime to regenerate ammonia (see Alkali AND CHLORINE PRODUCTS). 

The trivalent [P04] and [As04] ions react similarly. Examples of anions that give insoluble Hg(I) compounds in this way include halides, pseudohalides, halates, carboxylates and sulfate. A trace of HNO3 or HCIO4 is often added to the solution of the Hg(I) nitrate or perchlorate to prevent disproportionation induced by alkali. Table 1 lists common Hg(I) derivatives prepared in this way and includes values of the solubility products of the sparingly soluble Hg(I) compounds where these are measured. A similar reaction is used to prepare HgjCO, from a soluble bicarbonate ... 

Asymptomatic patients with mild to moderate acidemia (HCO3-, 12 to 20 mEq/L pH, 7.2 to 7.4) can usually be managed with gradual correction of the acidemia over days to weeks using oral sodium bicarbonate or other alkali preparations (Table 74-4). The dose of bicarbonate can be calculated as follows ... 

The reaction of aminoguanidine with sodium nitrite under neutral conditions yields tetra-zolylguanyltetrazene hydrate (85), a primary explosive commonly known as tetrazene. Tetrazene (85) is only formed in the absence of free mineral acid and so a common method for its preparation treats the bicarbonate salt of aminoguanidine (84) with one equivalent of acetic acid followed by addition of aqueous sodium nitrite. " Tetrazene (85) is decomposed by aqueous alkali to form triazonitrosoaminoguanidine (86) which is isolated as the cuprate salt (87) on addition of copper acetate to the reaction mixture. Acidification of the copper salt (87) with mineral acid leads to the formation of 5-azidotetrazole (88) (CHN7 = 88 % N).55 56... 

These benzoyl derivatives were prepared by shaking the amino acid with excess of benzoyl chloride in the presence of sodium bicarbonate instead of in the presence of excess of alkali, i.e., by the Schotten-Baumann method, which gave poor and varying yields of the benzoyl compound. 

Nickel carbonate forms many double salts, such as, Na2COs NiCOs IOH2O with alkali metal carbonates. However, such double carbonates usually are prepared by mixing an alkali metal or ammonium bicarbonate solution with a nickel salt solution, followed by crystallization. 

Arfwedson prepared lithium acetate, ignited it, and noted the insolubility of the resulting lithium carbonate in water and its action on platinum. He also prepared and studied the bicarbonate, sulfate, nitrate, chloride, tartrate, borate, hydroxide, and a double sulfate which he reported as lithium alum. He mentioned that lithium hydroxide is much less soluble than the other caustic alkalies and that it has a greater saturation capacity [lower equivalent weight] than they. Because of its ability to form deliquescent salts with nitric and hydrochloric acids, Arfwedson recognized the close relation between the new alkali and the alkaline earths, especially magnesia. 

The preparation of alkali carbonate from the alkali chlorides.—T. Bergman8 (1775) showed that a soln. of sodium chloride is decomposed by potassium carbonate, for the mixed soln. on evaporation gives a crop of crystals of potassium chloride, and this is followed by a crop of crystals of sodium carbonate. J. F. Meyer (1764), and J. F. Westrumb (1785) gave specific directions for the operation, and the same plan was recommended by C. F. S. Hahnemann, P. J. Karstellyn, and J. C. W. Render. Between 1802 and 1815 sodium carbonate was made at Walker-on-Tyne by a modification of the process devised by Earl of Dundonald (1795). C. Bischoff made sodium bicarbonate by passing carbon dioxide into an aq. soln. of equal parts of sodium chloride and potassium carbonate—sodium bicarbonate precipitated, potassium chloride remains in soln. W. Weldon patented a modification of this process in 1881. 

Phenolphthalein Paper. This paper is turned red by alkalis, induding ammonia and sodium carbonate solutions, but not bicarbonates. It can be used to advantage for differentiating among the alkalis. The paper is prepared by soaking filter paper in a hot solution of 1 gram of phenolphthalein in 1 liter of water. 

Potassium Uranyl Carbonate, K4U02(C03)a, may be prepared by the action of carbon dioxide on potassium uranyl cyanide, or by evaporating at moderate temperature a solution containing potassium bicarbonate and potassium uranate. It crystallises in small hexagonal prisms, which are stable in dry air and dissolve in cold water without decomposition. The solution is hydrolysed on warming, and the addition of alkali causes j recipitation of uranyl hydroxide. 

Acid-base reactions between alkali metal bicarbonate and citric or tartaric acid have been used for many years to produce pharmaceutical preparations that effervesce as soon as water is added. In such systems, it is practically impossible to achieve much more than an atmospheric saturation of the solution with respect to the released carbon dioxide. If the acid dissolves first, then the bulk of the reaction takes place in the saturated solution in close proximity to the undissolved bicarbonate particles. If the bicarbonate dissolves faster, the reaction essentially takes place near the surface of the undissolved acid. Such suspension systems do not favor supersaturation with respect to carbon dioxide because the particulate solids act as nuclei for bubble formations. 

The initial step in the preparation of a coprecipitated catalyst is the reaction between a solution of two or more metal salts and a base, generally a hydroxide, alkali carbonate or bicarbonate. The resulting precipitate may contain not only the insoluble hydroxides and/or carbonates but also a mixed metal compound if the solubility equilibria are favorable. Even if the formation of a mixed metal compound is not favorable, some of the support material is usually trapped in the active metal precipitate. This dilutes the precipitate and inhibits the formation of large crystals of the active metal compound. Smaller crystals are easier to reduce and give more finely divided metal particles. ... 

SOda, modified. (neutral soda). A combination of soda ash and bicarbonate of soda in definite proportions for purposes where an alkali is needed, ranging in causticity between bicarbonate of soda and soda ash. White, crystalline powders water-soluble and possessing valuable cleansing and purifying properties. Prepared in various strengths. 

J A Celia, S W Bacon. Preparation of dialkyl carbonates via phase-transfer-catalyzed alkylation of alkali metal carbonate and bicarbonate salts. J. Org. Chem 49 1122-1125, 1984. 

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