Thermal dissociation of chlorine trifluoride behind incident shock waves

Abstract

also estimate the thermodynamic quantities for the process HC1 (gas) + HC1 (ice) and find that AH0 = -21.68 kcal/mol, AGO = -7.88 kcal/mol, and Ai30 = -48.2 cal/(mol deg). These results are obtained using wellknown thermodynamic data for the process HC1 (gas) -t HC1 (water).20 The equilibrium constant, K = (concentration of HC1 in ice)/(activity of HC1 in water), is 6.39 X 10-6, 1.78 X 10+, and 2.14 X at temperatures of -4, -11, and -18", respectively.The mode of incorporation of chloride ion in ice and the path of diffusion is suggested by the large hexagonally shaped channels that appear in the ice structure. These channels define the C axis, and this is the direction of diffusion. It is proposed that diffusion proceeds through and dissolution occurs in these hexagonal channels. On the basis of the above model we may predict that diffusion perpendicular to the C axis should be much slower than diffusion along the C axis.The technique described in this paper should be applicable to solubility studies in other solids that have low melting points, as long as they can be prepared in the form of large single crystals. In cases where the solubility is appreciable, the requirement of large single crystals may be obviated. 93623The thermal dissociation of CIFa behind incident shock waves has been studied in the temperature range of 800-1300°K. The course of the dissociation was followed by means of ultraviolet absorption spectroscopy centered a t 2200 =k 250 A. Initial slope measurements gave a value of kl = 101a.5*'J-4 exp -[(28,200 f 1700)/ R T ] cc/mol sec for the rate constant of the reaction CIFa + M = C1F2 + F + M. The collision efficiency of ClF relative to argon was found to be 35 =k 5 to 1. Evidence is presented which favors a heat of formation for CIFz of -19 =t 2 kcal/mol a t OOK.

Theoretical models for peak migration in gel permeation chromatography

“…Explicit recognition of the possibility of chromatographic separations based on differences in the ability of solute molecules of different size to penetrate into voids within beads of a microporous column packing dates at least from Synge's discussion2 of the "molecular sieve" effect and reports of elution of polysaccharides and polypeptides in inverse order of molecular weight from starch gel columns by Lindqvist and Storgárds3 and Lathe and Ruthven. 4 The idea that size differences alone between solute molecules and pores could provide a means for effecting separations enjoyed rapid practical exploitation, and an extensive literature soon grew up on separation of biological macromolecules by passage of aqueous solutions through columns packed with swollen gels. Less than a decade ago this kind of chromatography also became a practical possibility for synthetic organic polymers when cross-linked polystyrene gels with controlled pore size were developed5 and made commercially available.…”

High-temperature chemistry of HCl and Cl2

“…The data from Jacobs and Giedt [94], van Thiel et al [95], and Carabetta and Palmer [96] are in good agreement and these data form the basis for the recommendation of Lloyd [91]. The third group of data, reported by Blauer et al [97] and Santoro et al [98], indicate a rate constant for Cl + Cl + Ar that is about a factor of five below the bulk data. Reactions of HCl with oxygen-containing radicals include…”

“…[94], and Blauer et al [97]. The data from Jacobs and Giedt and from Blauer et al were obtained for the reverse reaction and converted through the equilibrium constant in the present work.…”

Chlorine, Bromine, Iodine and Astatine

“…The thermal or photolytic dissociation of C1F 3 is thought to proceed via the formation of C1F 2 , for which Δ//>° is estimated to be ca. -1 9 kcal mol -1 861 . Substantiation of this view is, provided by the infrared spectrum reported for C1F 2 as produced by the photolysis of chlorine trifluoride or mixtures of chlorine monofluoride and fluorine isolated in an inert matrix at 16°K 861 ; the vibrational characteristics indicate that, whereas CI3 is linear, C1F 2 is bent with an apex angle of 136 ± 15°.…”