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Ammonia, thermodynamic properties

Ammonia is readily absorbed ia water to make ammonia liquor. Figure 2 summarizes the vapor—Hquid equiUbria of aqueous ammonia solutions and Figure 3 shows the solution vapor pressures. Additional thermodynamic properties may be found ia the Hterature (1,2). Considerable heat is evolved duriag the solution of ammonia ia water approximately 2180 kJ (520 kcal) of heat is evolved upon the dissolution of 1 kg of ammonia gas. [Pg.336]

The increasing ranges of pressure and temperature of interest to technology for an ever-increasing number of substances would necessitate additional tables in this subsection as well as in the subsec tion Thermodynamic Properties. Space restrictions preclude this. Hence, in the present revision, an attempt was made to update the fluid-compressibihty tables for selected fluids and to omit tables for other fluids. The reader is thus referred to the fourth edition for tables on miscellaneous gases at 0°C, acetylene, ammonia, ethane, ethylene, hydrogen-nitrogen mixtures, and methyl chloride. The reader is also... [Pg.184]

Erom thermodynamic properties of ammonia greater than a datum of -40°E ... [Pg.302]

A chart which correlates experimental P - V - T data for all gases is included as Figure 2.1 and this is known as the generalised compressibility-factor chart.(1) Use is made of reduced coordinates where the reduced temperature Tr, the reduced pressure Pr, and the reduced volume Vr are defined as the ratio of the actual temperature, pressure, and volume of the gas to the corresponding values of these properties at the critical state. It is found that, at a given value of Tr and Pr, nearly all gases have the same molar volume, compressibility factor, and other thermodynamic properties. This empirical relationship applies to within about 2 per cent for most gases the most important exception to the rule is ammonia. [Pg.35]

The problems associated with new synthesis gas processes are far greater than problems associated with gas processing plants or refineries because of water, salt, sludge, ammonia, and cresols present in the process streams. This paper attempts to identify the magnitude of the problems and methods for solving these problems. The problem of predicting the thermodynamic properties of nonpolar-polar mixtures by means of equations of state is also identified as an area needing study. [Pg.317]

It was also observed, in 1973, that the fast reduction of Cu ions by solvated electrons in liquid ammonia did not yield the metal and that, instead, molecular hydrogen was evolved [11]. These results were explained by assigning to the quasi-atomic state of the nascent metal, specific thermodynamical properties distinct from those of the bulk metal, which is stable under the same conditions. This concept implied that, as soon as formed, atoms and small clusters of a metal, even a noble metal, may exhibit much stronger reducing properties than the bulk metal, and may be spontaneously corroded by the solvent with simultaneous hydrogen evolution. It also implied that for a given metal the thermodynamics depended on the particle nuclearity (number of atoms reduced per particle), and it therefore provided a rationalized interpretation of other previous data [7,9,10]. Furthermore, experiments on the photoionization of silver atoms in solution demonstrated that their ionization potential was much lower than that of the bulk metal [12]. Moreover, it was shown that the redox potential of isolated silver atoms in water must... [Pg.579]

Gas and Liquid Phases. Equilibrium data (P-V-T) and thermodynamic properties for the single-component systems water (steam) and ammonia are complete and apparently of the best accuracy because of the extensive use of these substances in cyclic systems 14,20). [Pg.183]

Natl. Bur. Standards, Tables of Thermodynamic Properties of Ammonia, Circ. 142... [Pg.194]

A in aft) provided aft is obtained directly from experimental parameters that characterize the localized electron state. The data (64, 68, 69) for metal solutions in ammonia, methylamine, and HMPA are included in Fig. 22. Inherent in the Mott picture (124) is a major change in the thermodynamic properties of the solutions in the transition region. This important feature is discussed in Section IV,B. [Pg.172]

Until recently the ability to predict the vapor-liquid equilibrium of electrolyte systems was limited and only empirical or approximate methods using experimental data, such as that by Van Krevelen (7) for the ammonia-hydrogen sulfide-water system, were used to design sour water strippers. Recently several advances in the prediction and correlation of thermodynamic properties of electrolyte systems have been published by Pitzer (5), Meissner (4), and Bromley ). Edwards, Newman, and Prausnitz (2) established a similar framework for weak electrolyte systems. [Pg.305]

Some thermodynamic properties of ammonia are given in the table below. i... [Pg.350]

The values in Tables 2-23 to 2-26 were generated from the NIST REFPROP software (Lemmon, E. W, McLinden, M. O., and Huber, M. L., NIST Standard Reference Database 23 Reference Fluid Thermodynamic and Transport Properties—REFPROP, Version 7.0, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Md., 2002). The primary source for the properties of aqueous ammonia mixtures is R. Tillner-Roth and D. G. Friend, A Helmholtz Free Energy Formulation of the Thermodynamic Properties of the Mixture Water + Ammonia, /, Phys. Chem. Ref. Data 27 63-96(1998). [Pg.119]

As mentioned above, the bulk of picoline is produced today by condensation of acetaldehyde, formaldehyde and ammonia in the gas phase, which simultaneously produces large quantities of pyridine. A selective and suitable alternative method starting from these or similar simple molecules has yet to be developed. Given the thermodynamic properties of the molecules and reactions involved it does not seem likely to expect a selective process for 3-picoline in the near future following this strategy, although shape-selective catalysts may hold a key. [Pg.543]

Bomchil, G., Harris, N., Leslie, M., et al. (1979). Structure and dynamics of ammonia adsorbed on graphitized carbon black. Part 1. Adsorption isotherms and thermodynamic properties. J. Chem. Soc. Faraday Trans. 1, 75, 1535-41. [Pg.186]

A result of such thermodynamic properties is that generally nitrides are refractory in the sense of being difficult to sinter and to crystallize, yet at the same time they have high dissociation pressures. Nitride chemistry is also made more difficult by the fact that many nitrides readily react with water (or moist air) ultimately to form hydroxides and ammonia. It is almost certainly true that many of the nitrides reported in the older literature contain significant amounts of O and/or H. [Pg.309]


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See also in sourсe #XX -- [ Pg.285 ]

See also in sourсe #XX -- [ Pg.170 ]

See also in sourсe #XX -- [ Pg.50 , Pg.138 ]




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