Organic solvents halogenated hydrocarbons

In spite of some of the disadvantages of silica gel, it is a very useful sorbent. Most of the early work with silica gel use a single U-tube or a train of two or more U-tubes. The U-tubes held at least 10 g of silica gel and sometimes one arm of the tube held a desiccant to reduce humidity effects The commercial tubes now available contain 150 mg to 1.5 g of silica gel sealed in glass tubes. Silica 1 has been used for a wide range of organic solvents halogenated hydrocarbons and nitrogen dioxide Often chemicals collected on silica gel require analysis by HPLC or derivatization prior to analysis. 

Organic compounds and partial oxidation compounds (rubber and plastics, organic solvents, chlorinated hydrocarbons and fluorocarbons, volatile organic compounds, CH, etc.) Organometallic compounds Halogens and their compounds (As, AsH, etc.)... 

Aqueous mineral acids react with BF to yield the hydrates of BF or the hydroxyfluoroboric acids, fluoroboric acid, or boric acid. Solution in aqueous alkali gives the soluble salts of the hydroxyfluoroboric acids, fluoroboric acids, or boric acid. Boron trifluoride, slightly soluble in many organic solvents including saturated hydrocarbons (qv), halogenated hydrocarbons, and aromatic compounds, easily polymerizes unsaturated compounds such as butylenes (qv), styrene (qv), or vinyl esters, as well as easily cleaved cycHc molecules such as tetrahydrofuran (see Furan derivatives). Other molecules containing electron-donating atoms such as O, S, N, P, etc, eg, alcohols, acids, amines, phosphines, and ethers, may dissolve BF to produce soluble adducts. 

Chemical Properties and Reactivity. LLDPE is a saturated branched hydrocarbon. The most reactive parts of LLDPE molecules are the tertiary CH bonds in branches and the double bonds at chain ends. Although LLDPE is nonreactive with both inorganic and organic acids, it can form sulfo-compounds in concentrated solutions of H2SO4 (>70%) at elevated temperatures and can also be nitrated with concentrated HNO. LLDPE is also stable in alkaline and salt solutions. At room temperature, LLDPE resins are not soluble in any known solvent (except for those fractions with the highest branching contents) at temperatures above 80—100°C, however, the resins can be dissolved in various aromatic, aUphatic, and halogenated hydrocarbons such as xylenes, tetralin, decalin, and chlorobenzenes. 

As esters the alkyl halides are hydrolysed by alkalis to alcohols and salts of halogen acids. They are converted by nascent hydrogen into hydrocarbons, by ammonia into amines, by alkoxides into ethers, by alkali hydrogen sulphides into mercaptans, by potassium cyanide into nitriles, and by sodium acetate into acetic esters. (Formulate these reactions.) The alkyl halides are practically insoluble in water but are, on the other hand, miscible with organic solvents. As a consequence of the great affinity of iodine for silver, the alkyl iodides are almost instantaneously decomposed by aqueous-alcoholic silver nitrate solution, and so yield silver iodide and alcohol. The important method of Ziesel for the quantitative determination of alkyl groups combined in the form of ethers, depends on this property (cf. p. 80). 

Volatile organic compounds (VOC) contribute to the formation of tropospheric ozone (summer smog). Certain halogenated hydrocarbons (e.g. CFCs) also destroy the stratospheric ozone layer. Chlorinated solvents are hazardous to water and, if disposed of incorrectly (e.g. burning), may emit highly toxic substances (e.g. dioxins). 

According to the vendor, the in situ bioremediation treatment system is applicable to soils contaminated with volatile organic compounds (VOCs) and semivolatile compounds, including those comprising various fuels, hydrocarbons, and solvents. The use of methane as an easily oxidized co-metabolite makes the technology amenable to treating soils contaminated with halogenated hydrocarbons. 

---