Measuring density will be almost the same as you did in the previous lab.
It appears Chemical determination of an unknown liquid that crude hydrofluoric acid was first prepared by an unknown English glassworker in In the Swedish chemist Carl Wilhelm Scheele obtained hydrofluoric acid in an impure state by heating fluorspar with concentrated sulfuric acid in a glass retort, which was greatly corroded by the product; as a result, vessels made of metal were used in subsequent experiments with the substance.
Fluorspar was then recognized to be calcium fluoride. The isolation of fluorine was for a long time one of the chief unsolved problems in inorganic chemistryand it was not until that the French chemist Henri Moissan prepared the element by electrolyzing a solution of potassium hydrogen fluoride in hydrogen fluoride.
He received the Nobel Prize for Chemistry for isolating fluorine. The difficulty in handling the element and its toxic properties contributed to the slow progress in fluorine chemistry.
Indeed, up to the time of World War II the element appeared to be a laboratory curiosity. Then, however, the use of uranium hexafluoride in the separation of uranium isotopesalong with the development of organic fluorine compounds of industrial importance, made fluorine an industrial chemical of considerable use.
Occurrence and distribution The fluorine-containing mineral fluorspar fluoriteCaF2 has been used for centuries as a flux cleansing agent in various metallurgical processes. The colourless, transparent crystals of fluorspar exhibit a bluish tinge when illuminatedand this property is accordingly known as fluorescence.
Fluorine is found in nature only in the form of its chemical compoundsexcept for trace amounts of the free element in fluorspar that has been subjected to radiation from radium. Not a rare element, it makes up about 0.
The principal fluorine-containing minerals are 1 fluorspar, deposits of which occur in Illinois, Kentucky, Derbyshire, southern Germany, the south of France, and Russia and the chief source of fluorine, 2 cryolite Na3AlF6chiefly from Greenland, 3 fluoroapatite Ca5[PO4]3[F,Cl]widely distributed and containing variable amounts of fluorine and chlorine4 topaz Al2SiO4[F,OH]2the gemstoneand 5 lepidolitea mica as well as a component of animal bones and teeth.
Physical and chemical properties At room temperature fluorine is a faintly yellow gas with an irritating odour. Inhalation of the gas is dangerous. Upon cooling fluorine becomes a yellow liquid. There is only one stable isotope of the element, fluorine Because fluorine is the most electronegative of the elements, atomic groupings rich in fluorine are often negatively charged.
Fluorine is the most powerfully oxidizing element. No other substance, therefore, is able to oxidize the fluoride anion to the free element, and for this reason the element is not found in the free state in nature.
For more than years, all chemical methods had failed to produce the element, success having been achieved only by the use of electrolytic methods. However, in American chemist Karl O. The high oxidizing power of fluorine allows the element to produce the highest oxidation numbers possible in other elements, and many high oxidation state fluorides of elements are known for which there are no other corresponding halides—e.
Fluorine F2composed of two fluorine atomscombines with all other elements except helium and neon to form ionic or covalent fluorides.
Some metals, such as nickelare quickly covered by a fluoride layer, which prevents further attack of the metal by the element. Certain dry metals, such as mild steelcopperaluminumor Monel a 66 percent nickel, When lubricants are required, fluorocarbon oils are most suitable.
Fluorine reacts violently with organic matter such as rubber, wood, and clothand controlled fluorination of organic compounds by the action of elemental fluorine is only possible if special precautions are taken.
Production and use Fluorspar is the most important source of fluorine. In the manufacture of hydrogen fluoride HFpowdered fluorspar is distilled with concentrated sulfuric acid in a lead or cast-iron apparatus.
The hydrogen fluoride is obtained in a fairly anhydrous state by fractional distillation in copper or steel vessels and is stored in steel cylinders. The usual impurities in commercial hydrogen fluoride are sulfurous and sulfuric acids, as well as fluorosilicic acid H2SiF6arising from the presence of silica in the fluorspar.
Hydrogen fluoride is employed in the preparation of numerous inorganic and organic fluorine compounds of commercial importance—for example, sodium aluminum fluoride Na3AlF6used as an electrolyte in the electrolytic smelting of aluminum metal.
A solution of hydrogen fluoride gas in water is called hydrofluoric acidlarge quantities of which are consumed in industry for cleaning metals and for polishing, frosting, and etching glass. The preparation of the free element is carried out by electrolytic procedures in the absence of water.
Generally these take the form of electrolysis of a melt of potassium fluoride—hydrogen fluoride in a ratio of 1 to 2. During the process the hydrogen fluoride content of the electrolyte is decreased, and the melting point rises; it is therefore necessary to add hydrogen fluoride continuously.
Fluorine can be safely stored under pressure in cylinders of stainless steel if the valves of the cylinders are free from traces of organic matter. The element is used for the preparation of various fluorides, such as chlorine trifluoride ClF3sulfur hexafluoride SF6or cobalt trifluoride CoF3.
The chlorine and cobalt compounds are important fluorinating agents for organic compounds. With appropriate precautions, the element itself may be used for the fluorination of organic compounds. Sulfur hexafluoride is used as a gaseous electrical insulator.
Elemental fluorine, often diluted with nitrogenreacts with hydrocarbons to form corresponding fluorocarbons in which some or all hydrogen has been replaced by fluorine.unknown liquid based on its characteristic chemical reactions.
We will become familiar with the signs and observations that or a mixture of two or more chemicals, it is often necessary to determine whether a test provides an inclusive, exclusive or indeterminate answer.
A test would be considered inclusive if the result indicated that a. Determination of the Identity of an unknown liquid My Name The date My period Partner #1 name Partner #2 name Purpose: The purpose of this lab is to determine the identity of an unknown liquid by measuring its density, melting point, boiling point, and solubility in both water and alcohol, and then.
lab chemical analysis techniques. Chemical analysis covers a wide range of techniques and an even broader range of samples including solids, liquids and gases from raw materials to finished pfmlures.comis may involve using a particular or combination of techniques and may be related to a specific problem to solve or product of process .
PENTACHLOROPHENOL (PCP) International Programme on Chemical Safety Poisons Information Monograph Chemical 1. NAME . Chemical waste may include. old and/or expired chemicals, chemical waste solutions, or; debris contaminated with chemicals; UVM is committed to managing its chemical waste in a way that prevents release to the environment.
Fluorine (F), most reactive chemical element and the lightest member of the halogen elements, or Group 17 (Group VIIa) of the periodic pfmlures.com chemical activity can be attributed to its extreme ability to attract electrons (it is the most electronegative element) and to the small size of its atoms.