http___en.m.wikipedia.org_wiki_Potassium_carbonate.xml
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Калиев карбонат Калиевият карбонат, наричан още поташ, е бяла сол, разтворима във вода и неразтворима в алкохол. Като сол на силна основа (калиева основа) и слаба киселина (въглеродна киселина) водните ̀и разтвори имат основен (алкален) характер. Реагира със силни киселини с отделяне на въглероден диоксид: Калиевият карбонат може да се получи ако се остави калиева основа на въздуха: В древността е била добивана от растителна пепел, която има сравнително високо съдържание на калиев карбонат (50-80 %). За разлика от натриевия карбонат, калиевият карбонат не може да се получи по метода на Солвей, тъй като междинният продукт калиев хидрогенкарбонат е много добре разтворим във вода. Може да се използва за получаването на други съединения на калия: Използва се още при производството на течен (калиев) сапун и стъкло. В готварството се използва като хранителна добавка (Е501) подобно на натриевия бикарбонат. Приложение намира и като електролит (стопилка) в горивни елементи.
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Potassium carbonate (K2CO3) is a white salt, soluble in water (insoluble in ethanol[2]), which forms a strongly alkaline solution. It can be made as the product of potassium hydroxide's absorbent reaction with carbon dioxide. It is deliquescent, often appearing a damp or wet solid. Potassium carbonate is used in the production of soap and glass. HistoryEdit Potassium carbonate was first identified in 1742 by Antonio Campanella and is the primary component of potash and the more refined pearl ash or salts of tartar. Historically, pearl ash was created by baking potash in a kiln to remove impurities. The fine, white powder remaining was the pearl ash. The first patent issued by the US Patent Office was awarded to Samuel Hopkins in 1790 for an improved method of making potash and pearl ash. In late 18th century North America, before the development of baking powder, pearl ash was used as a leavening agent in quick breads.[3] Other terms for potassium carbonate: - Carbonate of potash - Dipotassium carbonate - Dipotassium salt - Pearl ash - Potash - Salt of tartar - Salt of wormwood ProductionEdit Today, potassium carbonate is prepared commercially by the electrolysis of potassium chloride. The resulting potassium hydroxide is then carbonated using carbon dioxide to form potassium carbonate, which is often used to produce other potassium compounds. - 2KOH + CO2 → K2CO3 + H2O ApplicationsEdit - (historically) for soap, glass, and china production - as a mild drying agent where other drying agents, such as calcium chloride and magnesium sulfate, may be incompatible. It is not suitable for acidic compounds, but can be useful for drying an organic phase if one has a small amount of acidic impurity. It may also be used to dry some ketones, alcohols, and amines prior to distillation.[4] - to make a safer electrolyte for oxyhydrogen production than potassium hydroxide, the more commonly used electrolyte. - In cuisine, it is used as an ingredient in the production of grass jelly, a food consumed in Chinese and Southeast Asian cuisines. It is used to tenderize tripe. German gingerbread recipes often use potassium carbonate as a baking agent. - as a buffering agent in the production of mead or wine. - softening hard water.[5] - as a fire suppressant in extinguishing deep-fat fryers and various other B class-related fires - in condensed aerosol fire suppression, although as the byproduct of potassium nitrate. - an ingredient in welding fluxes, and in the flux coating on arc-welding rods. - it is also used in gunpowder as a stable source of energy. - stability in neurons to help maintain equilibrium. - as an animal feed ingredient to satisfy the potassium requirements of farmed animals such as broiler breeders ReferencesEdit - ^ http://chem.sis.nlm.nih.gov/chemidplus/rn/584-08-7 - ^ http://www.researchgate.net/publication/231535294_Solubility_of_Potassium_Carbonate_and_Potassium_Hydrocarbonate_in_Methanol - ^ See references to "pearl ash" in "American Cookery" by Amelia Simmons, printed by Hudson & Goodwin, Hartford, 1796. - ^ Leonard, J.; Lygo, B.; Procter, G. "Advanced Practical Organic Chemistry" 1998, Stanley Thomas Publishers Ltd - ^ Child, Lydia M. "The American Frugal Housewife" 1832 BibliographyEdit A Dictionary of Science, Oxford University Press, New York, 2003