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Melting alternating

Carbon tetrafluoride [75-73-0] M 88.0, b -15 . Purified by repeated passage over activated charcoal at solid-C02 temperatures. Traces of air were removed by evacuating while alternately freezing and melting. Alternatively, liquefied by cooling in liquid air and then fractionally distilled under vacuum. (The chief impurity originally present was probably CF3CI). [Pg.157]

A slow method is to wait until the ice that has condensed on the walls of the flask has all melted. Alternatively, the flask may be immersed in a methanol bath. [Pg.24]

Shallow-mantle xenoliths, hosted in alkali basalts, commonly contain C02-rich fluid inclusions (e.g., Roedder, 1965, 1984 Frey and Prinz, 1978 Murck eta/., 1978 Miller and Richter, 1982 Pasteris, 1987 Frezzotti et al., 1994 Bumard et al., 1998 Ertan and Leeman, 1999 Andersen and Neumann, 2001). In most cases, these fluid inclusions are related to metasomatic processes to which the samples were subjected. As outlined previously, the C02-rich nature of these inclusions may be a natural consequence of degassing from an ascending melt that contains both H2O and CO2, because the greater solubility of H2O in sihcate melts would allow it to remain in solution in the residual melt. Alternatively, as proposed by Andersen and Neumann (2001), the high CO2 content in these inclusions could be the result of removal of water via reactions between the original fluid and the host mineral surrounding the inclusion. [Pg.1042]

The precise nature of the chondrule-form-ing event, the "chondrule factory," is also the subject of some discussion. Some workers favor the formation of chondrules by the direct condensation of the solar nebula gas as a melt. Alternatively, chondrules could be the residues of evaporation. The presence of relict olivine grains in some chondrules (Jones, 1996) argues against a simple condensation model and may imply multiple condensation-evaporation events. [Pg.47]

Lead(II) fluoride is obtained as a white crystalUne powder by dissolving lead carbonate in hydrofluoric acid and decomposing the hydrofluoride formed by rapid melting. Alternatively it is prepared from lead metal and anhydrous hydrofluoric add at 160° under autogenous pressure. [Pg.135]


See other pages where Melting alternating is mentioned: [Pg.554]    [Pg.223]    [Pg.406]    [Pg.90]    [Pg.131]    [Pg.321]    [Pg.1807]    [Pg.90]    [Pg.287]    [Pg.79]    [Pg.422]    [Pg.267]    [Pg.6235]    [Pg.334]    [Pg.377]    [Pg.130]    [Pg.480]    [Pg.554]    [Pg.928]    [Pg.291]    [Pg.110]    [Pg.532]    [Pg.26]   
See also in sourсe #XX -- [ Pg.751 , Pg.751 , Pg.752 , Pg.752 , Pg.753 ]




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