Krypton entropy

Values extracted and in some cases rounded off from those cited in Rabinovich (ed.), Theimophysical Fropeities of Neon, Argon, Krypton and Xenon, Standards Press, Moscow, 1976. This source contains an exhaustive tabulation of values, v = specific volume, mVkg h = specific enthalpy, kj/kg s = specific entropy, kJ/(kg-K). The notation 6.76.—3 signifies 6.76 x 10 . This book was published in English translation by Hemisphere, New York, 1988 (604 pp.). 

Differential Entropies in H-Zeolites. The differential entropies, Ss, of krypton in the three H-zeolites were derived for each uptake from the relation... 

Values of Ki are given for krypton in Table IV for selected temperatures together with the coefficients Ko in the relation Ki = K0 exp — AE0/ RT, and the standard energies and entropies AE° and AS0 defined, respectively, by... 

The virial isotherm equation, which can represent experimental isotherm contours well, gives Henry s law at low pressures and provides a basis for obtaining the fundamental constants of sorption equilibria. A further step is to employ statistical and quantum mechanical procedures to calculate equilibrium constants and standard energies and entropies for comparison with those measured. In this direction moderate success has already been achieved in other systems, such as the gas hydrates 25, 26) and several gas-zeolite systems 14, 17, 18, 27). In the present work AS6 for krypton has been interpreted in terms of statistical thermodynamic models. 

Pure component experimental data for sorption of methane and krypton on 5A zeolite at 238, 255. and 271K, and in the pressure range of 0 to 97.36 kPa were also obtained during this work (shown in Figures 3 and U). Further sorption data for methane on 5A zeolite (10, 13, 1 0, and for krypton on 5A zeolite (10. 15) are also plotted for other temperatures, all of which appear to be consistent. These experimental data were used to derive the energy and entropy parameters in equation U for the isotherm model of Schirmer et al. by a minimization of a sum of squares optimization procedure. 

As the two sorbates methane and krypton on 5A appeared to have different mechanistic behaviour, further theoretical study appeared warranted. Two hypothetical gases P and Q whose properties are tabulated in Table 1 were used for comparison with the behaviour of methane and krypton. Hypothetical gas P was designed to have a Henry constant equal to methane, but to be a localized sorbate having entropy of sorption values decreasing incrementally as for krypton. Conversely, hypothetical gas Q had a Henry constant equal to that of krypton, but entropy of sorption values non-localized and decreasing incrementally as for methane. 

Figure 4. Net differential entropy of adsorption of krypton on ground muscovite...

From our krypton adsorption data, we must conclude that the adsorption energetics are the same within experimental error on all three mica samples for the range 0.2 <0< 0.8 (with the possible exception of the barium muscovite up to 0 0.4, as noted above). We have calculated differential heats and entropies... 

We may assume that both argon and krypton adsorbed on mica are essentially two-dimensional liquids at the completion of the first monolayer (2, 4). The rise in the entropy functions for argon adsorption on potassium and barium mica as the monolayer point is approached may then reflect the transition from substantially localized adsorption at lower coverages to a mobile film. No such phenomenon is observed with krypton, suggesting that there is no change in the behavior of the adsorbed phase during formation of most of the first monolayer. 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed.), Thermophysical Properties of Neon, At on, Krypton and Xenon, Standards Press, Moscow, 1976. v = specific volume, mVkg h = specific enthalpy, kj/kg s = specific entropy, kJ/(kg-K). This source contains an exhaustive tabulation of values. The notation 7.420.-4 signifies 7.420 x 10". This book was published in English translation by Hemisphere, New York, 1988 (604 pp.). The 1993 ASHRAE Handbook—Fundamentals (SI ed.) has a thermodynamic chart for pressures from 1 to 2000 bar, temperatures from 90 to 700 K. Saturation and superheat tables and a chart to 50,000 psia, 1220 R appear in Stewart, R. B., R. T. Jacobsen, et al.. Thermodynamic Properties of Refrigerants, ASHRAE, Atlanta, GA, 1986 (521 pp.). For specific heat, thermal conductivity, and viscosity see Thermophysical Properties of Refrigerants, ASHRAE, 1993. 

The BKW calculations were performed with Krypton gas entropy fits obtained using the TDF code described in Appendix F and data from NBS Circular 467. The Krypton term value is 112.04 with a weight of 4. and an initial weight of 2. 

Kr < CI2 < SO3. Because Krypton is a monoatomic gas, it has the least entropy. Because SO3 is the most complex molecule, it has the most entropy. The molar masses of the three gases vary slightly, but not enough to overcome the differences in molecular complexity. 

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