| 单词 | dichromate |
| 例句 | The contamination was first detected more than a decade ago, and officials traced it to potassium dichromate used to prevent corrosion inside cooling towers at Los Alamos lab's power plant. Federal and state regulators have set their focus on cleaning up a plume of chromium contamination near the border of the San Ildefonso Pueblo, a New Mexico tribal community 2016-04-04T04:00:00Z “These plaintiffs were not exposed to dangerous amounts of sodium dichromate and did not suffer any damages as a result of anything KBR did or did not do,” Harrison said. Court vacates $85 million award for Oregon National Guardsmen in Iraq health case 2015-05-14T04:00:00Z Vowing revenge, Bond, a laboratory technician, stole the chemical 10-chloro-10H phenoxarsine from the company where she worked and purchased potassium dichromate on Amazon.com. Justices: Treaty can't be invoked in assault case 2014-06-02T04:00:00Z Court documents filed for the guardsmen said that much of the sodium dichromate was in powder form and blowing around the plant. Oregon guardsmen say were knowingly exposed to toxic chemicals in Iraq 2012-10-11T01:41:20Z A salt containing two parts of chromic acid to one of the other ingredients; as, potassfum bichromate; Ð called also dichromate. Webster's Unabridged Dictionary (2nd 100 Pages) 2012-03-24T02:00:19.387Z In September, the local government arrested five people for the dumping and ordered the company to halt production of chromium and sodium dichromate. China cancer village tests reach of law against pollution 2012-01-16T12:34:33Z The principle of the process is this: An organic tacky substance is sensitized with potassium dichromate, and exposed under a reversed positive to the action of light. Photogravure 2011-06-19T02:00:24.663Z The latter is prepared by oxidizing the anthracene—previously reduced by sublimation to the condition of a very finely-divided crystalline powder—with sulphuric acid and potassium dichromate. Coal and What We Get from It Since the chromate changes into a dichromate in the presence of an acid, it will be sufficient to study the action of the dichromates alone. An Elementary Study of Chemistry On boiling it with copperas it becomes violet, while on boiling with potassium dichromate it changes to a yellowish brown. Scientific American Supplement, No. 363, December 16, 1882 It consists of a Bunsen battery that I activate not with potassium dichromate but with sodium. Twenty Thousand Leagues Under the Sea Dextrine 60 grains White sugar 75 grains Ammonium dichromate 30 grains Glycerine 2 to 8 minims Distilled water 3 ounces The gum is first dissolved and the remainder of the ingredients added. Photogravure 2011-06-19T02:00:24.663Z Commercial sodium dichromate is hygroscopic and contains varying amounts of water. Organic Syntheses It will be noticed that the oxidizing action of potassium dichromate leaves potassium sulphate and chromium sulphate as the products of the reaction. An Elementary Study of Chemistry When a dilute solution of a chromate or dichromate is acidified with an acid, such as sulphuric acid, no reaction apparently takes place. An Elementary Study of Chemistry The platinum wires extending into the tubes B and D are now connected with the wires leading from two or three dichromate cells joined in series. An Elementary Study of Chemistry After this it is well washed to remove the unaltered gum and dichromate salt. Photogravure 2011-06-19T02:00:24.663Z A concentrated solution of technical sodium dichromate is prepared by dissolving 140 g. in 65 cc. of water. Organic Syntheses On evaporating the solution these substances crystallize out as potassium chrome alum, which substance is produced as a by-product in the industries using potassium dichromate for oxidizing purposes. An Elementary Study of Chemistry Their salts, the chromates and dichromates, are important compounds. An Elementary Study of Chemistry This is the best known dichromate, and is the most familiar chromium compound. An Elementary Study of Chemistry This is performed in a solution of potassium dichromate rendered alkaline with ammonia. Photogravure 2011-06-19T02:00:24.663Z At first a greenish-black precipitate forms, but upon further addition of the sodium dichromate solution, the color changes to yellowish green. Organic Syntheses Potassium dichromate finds use in many industries as an oxidizing agent, especially in the preparation of organic substances, such as the dye alizarin, and in the construction of several varieties of electric batteries. An Elementary Study of Chemistry When technical sodium dichromate is used, the solution should be filtered with suction, before it is added to the hydroquinone, in order to remove any insoluble impurities. Organic Syntheses In all 540 g. of sodium dichromate are added, the addition taking one to two hours. Organic Syntheses It is sometimes advisable to regulate the quantity of dichromate. Photogravure 2011-06-19T02:00:24.663Z This requires about one-half to three-quarters of an hour; 90 to 110 cc. of sodium dichromate solution is necessary. Organic Syntheses The reason why the potassium salt rather than the sodium compound is used is that sodium chromate and dichromate are so soluble that it is hard to prepare them pure. An Elementary Study of Chemistry It is essential that the stirring should be most efficient, so that when the mixture becomes thick the dichromate will be evenly distributed throughout the liquid, as rapidly as it is added. Organic Syntheses Technical sodium dichromate generally contains a certain amount of chlorides, and the chlorine liberated from these tends to cause a troublesome foam towards the end, of the reaction. Organic Syntheses The amount of solid sodium dichromate given is for the dry crystalline compound containing two molecules of water of crystallization. Organic Syntheses |
| 随便看 |
|
英语例句辞典收录了117811条英语例句在线翻译词条，基本涵盖了全部常用单词及词组的例句翻译及用法，是英语学习的有利工具。