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Lithium fluoride formation

In both cases, the fluorination of the complex oxides of tantalum and niobium leads to the formation of the water-soluble compounds (NH4)2TaF7 and (NH4)3NbOF6, the insoluble lithium fluoride and die gaseous components H20, NH3 and HF. [Pg.264]

C08-0076. Calculate the overall energy change for the formation of lithium fluoride from lithium metal and fluorine gas. hi addition to data found in Appendix C and Table 8-4. the following information is needed The bond energy of F2 is 155 kJ/mol, and lithium s enthalpy of vaporization is 159.3 kJ/mol. [Pg.562]

Using Lewis symbols, write a balanced chemical equation showing the formation of lithium fluoride, LiF, from isolated lithium and fluorine atoms. [Pg.142]

The same principles that are valid for the surface of crystalline substances hold for the surface of amorphous solids. Crystals can be of the purely ionic type, e.g., NaF, or of the purely covalent type, e.g., diamond. Most substances, however, are somewhere in between these extremes [even in lithium fluoride, a slight tendency towards bond formation between cations and anions has been shown by precise determinations of the electron density distribution (/)]. Mostly, amorphous solids are found with predominantly covalent bonds. As with liquids, there is usually some close-range ordering of the atoms similar to the ordering in the corresponding crystalline structures. Obviously, this is caused by the tendency of the atoms to retain their normal electron configuration, such as the sp hybridization of silicon in silica. Here, too, transitions from crystalline to amorphous do occur. The microcrystalline forms of carbon which are structurally descended from graphite are an example. [Pg.180]

It is believed that the discharge mechanism involves the formation of an intermediate lithium intercalation compound in which both lithium and fluorine are situated between the carbon layers of the graphitic structure. The carbon formed is graphitic and improves the cell performance as the discharge progresses, leading to a high cathode utilization - close to 100% for low currents. The lithium fluoride precipitates. [Pg.119]

There has been a review of didehydropyridines, focusing on then formation from halopyridines and base.123 The reactions of tri-p-tolyloxonium salts with hydroxide in water yield a mixture of p- and m-cresols via a benzyne intermediate,124 as shown in Scheme 7. A benzyne intermediate, generated by loss of lithium fluoride, is also implicated in the reaction of organolithium reagents with fluoro-AyV-diallylanilincs leading to 3,4-disubstituted indolines.125 The reaction of benzyne with 1,8-diethynylnaphthalene has been shown to yield benzo [a]pyrene.126... [Pg.254]

Lithium fluoride is able to promote the formation of azomethine ylids from /V-benzyl-/V-(met hox y met hy I)tri met h y I s i I y I met h y I am i ne. The reaction with methyl fumarate and maleate gives quantitative yields of trans and cis /V-benzyl-3,4-dicarbomethoxypyrro-lidines. Thus, the geometry of the alkenes is preserved during the cycloaddition reaction. These results are identical to those obtained using Achiwa s procedure (see Section VII.D.2). [Pg.325]

In spite of the efficiency of lithium fluoride to initiate formation of an azomethine ylid from aminomethylethers, sonication of the reaction medium proved useful. It is likely that sonication improves the solubility of lithium fluoride in the solvent. This is illustrated by the following two examples. Chiral pyrrolidinylfuranones are obtained from 5-(S)-5-menthyloxy-4-vinylfuran-2(5H)-one. Sonication increases the yield from 55 to 88%, but does not change the stereoselectivity.440... [Pg.326]

These two reaction equations can be summed (the electrons cancel) to show the formation of lithium fluoride, an ionic compound. [Pg.4]

Petersen 9 has determined the heat of formation of lithium fluoride from the hydroxide in dilute aqueous solution ... [Pg.59]

By combining the heat of neutralization given by the foregoing equation with the heats of formation of water, dissolved lithium hydroxide, and dissolved hydrogen fluoride, an equation is obtained giving the heat of formation of dissolved lithium fluoride from lithium, fluorine, and water ... [Pg.59]

There are two fluorination reactions with ester substrates reported in the literature which consist of only a single example each. One is the formation of fluoroethene from acetoxyethene and lithium fluoride in the presence of palladium acetate. The other is formation of fluoro-ethane from ethyl orthoformate with silicon tetrafluoride. - ... [Pg.131]

We can illustrate the energy changes involved in the formation of an ionic solid by considering the formation of solid lithium fluoride from its elements ... [Pg.598]

Formation of solid lithium fluoride from the gaseous Li+ and F ions ... [Pg.598]

In discussing the energetics of the formation of solid lithium fluoride, we emphasized the importance of lattice energy in contributing to the stability of the ionic solid. Lattice energy can be represented by a modified form of Coulomb s law,... [Pg.600]

Formation of ionic compounds from the elements appears to be one of the simpler overall reactions, but can also be written as a series of steps adding up to the overall reaction. The Born-Haber cycle is the process of considering the series of component reactions that can be imagined as the individual steps in compound formation. For the example of lithium fluoride, the first five reactions added together result in the sixth overall reaction. [Pg.220]

Reference has already been made to the high lattice energies of crystalline compounds containing small ions lithium fluoride is such a compound, and its high heat of formation and low solubility are not unexpected. [Pg.249]


See other pages where Lithium fluoride formation is mentioned: [Pg.58]    [Pg.58]    [Pg.127]    [Pg.18]    [Pg.443]    [Pg.450]    [Pg.127]    [Pg.100]    [Pg.77]    [Pg.512]    [Pg.514]    [Pg.62]    [Pg.221]    [Pg.4]    [Pg.4]    [Pg.193]    [Pg.374]    [Pg.519]    [Pg.4]    [Pg.476]    [Pg.75]    [Pg.599]    [Pg.4]    [Pg.476]    [Pg.512]    [Pg.514]    [Pg.70]   
See also in sourсe #XX -- [ Pg.4 ]




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