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无极刀银虫 (著名写手)
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50金币球连四硫酸钾的制备
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如题哦 要生产这个东西 但找不到相关的方法 不知道大家有什么好的建议没有哦？ |
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3楼2008-04-05 22:19:35
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A two- to three-liter stoppered glass flask is used to saturate 750 ml. of H2O with SO3 at 0°C. Disregarding the appearance of any crystalline SO3 • 6H2O, the solution is reacted at 0°C with 100-ml. portions of a solution of 75 g. of S2C12 in 500 ml. of petroleum ether precooled to -15°C. The liquid turns yellow in the process; it must be decolorized before the addition of a new portion by vigorous shaking, following which it is cooled to 0°C. At the end of the addition, the mixture should still have an odor of SO3. The petroleum ether is removed in a separatory funnel, and a fast air stream is passed through the aqueous layer for several hours until no further odor of SO3 can be detected. The solution is then cooled to 0°C and neutralized with an ice-cold solution of 150 g. of KOH in one liter of aqueous alcohol (final pH 6-7). The precipitated K2S4O6, which still contains about 10% KC1, is suction-filtered and dried on clay at room temperature. The yield is about 165 g. To purify the crude product, it is dissolved in 120 ml. of 70°C water, thoroughly stirred, and, if necessary, reheated rapidly to 60°C. It is then filtered rapidly through a heated funnel; long heating or temperatures above 60°C must be avoided because of the instability of K2S4O6. On cooling to 0°C, the filtrate yields 120 g. of 100% K2S4O6. The crystals are filtered by suction, washed with 150 ml. of aqueous alcohol, and dried by pressing on clay at room temperature. By adding the wash alcohol to the mother liquor, a further 20 g. of 99% pure salt can be precipitated. 2K2S2O3 + I2 = K2S4O6 + 2KI An aqueous, nearly saturated solution of 39.5 g. of K2S2O3 •2H2O (sulfate-free) is added very slowly (drop-by-drop) to an ice-cooled solution of 26 g. of I2 in a mixture of ethanol and a few milliliters of H2O. Very vigorous stirring is needed during the addition. The reaction is instantaneous; thetetrathionate, which is insoluble in ethanol, separates as small crystals. At the end of the addition, the solution is suction-filtered and washed with alcohol until the wash liquor is free of iodine and iodide. To purify the salt, it is redissolved at room temperature in as little water as possible and reprecipitated with alcohol. The precipitate (small, shiny crystals) is completely pure. It is dried by pressing between filter papers and then in a desiccator over concentrated H2SO4. PROPERTIES: Colorless, platelike or prismatic crystals; the pure dry material is stable for a very long time without change but decomposes if K2S2O3 or occluded mother liquor is present, assuming a characteristic odor. On ignition, K2S4O6 decomposes to K2SO4, SO3 and S. |
2楼2008-03-26 21:40:43