Nonpolar gases

Zwanzig R 1954 High temperature equation of state by a perturbation method I. Nonpolar Gases J. Chem. Phys. 22 1420... 

Pierotti R 1965. Aqueous Solutions of Nonpolar Gases. Journal of Physical Chemistry 69 281-288. 

Zwanzig R W 1954. High-temperature Equation of State by a Perturbation Method. 1. Nonpolar Gases. Journal of Chemical Physics 22 1420-1426. 

For prediction of vapor density of pm e hydi ocaihon and nonpolar gases, tbe corresponding states method of Pitzer et al. is tbe most accurate method, witb errors of less than 1 percent except in tbe critical region where errors of up to 30 percent can occur. Tbe method correlates tbe compressibibty factor by Eq. (2-75), after which tbe density can be calculated by Eq. (2-75) ... 

Nonpolar gases are only slightly soluble in water. For example, water in contact with the Earth s atmosphere contains O2 at a concentration of only about 2.5 x 10 M and CO2 at about 1 x 10 M. Nevertheless, these small concentrations are essential for aquatic life. Fish and other aquatic animals use their gills to extract O2 dissolved in water, and unless that oxygen is replenished, these species die. Submerged green plants carry out photosynthesis using dissolved carbon dioxide, which also must be replenished for these plants to survive. 

All the molarities are rather small, in the 10 to lO " M range. Given that these are nonpolar gases, it does make sense that their solubilities are small in a polar solvent such as water. 

This intermolecular attraction occurs in all substances, but is significant only when the other types of intermolecular forces are absent. It arises from a momentary distortion of the electron cloud, with the creation of a very weak dipole. The weak dipole induces a dipole in another nonpolar molecule. This is an extremely weak interaction, but it is strong enough to allow us to liquefy nonpolar gases such as hydrogen, H2, and nitrogen, N2. If there were no intermolecular forces attracting these molecules, it would be impossible to liquefy them. 

Shoar, S. K. Gubbins, K. E. "Solubility of Nonpolar Gases in Concentrated Electrolyte Solutions" J. Phys. 

This article consists of a review of certain specific effects that occur during the process of physical adsorption, in which the writer has been especially interested. While it is hoped that all work directly relevant to these aspects of adsorption has been covered in a comprehensive manner, this review does not aim to cover all the specific effects that are known to occur on adsorption. Some surprise may be occasioned by the title, as the statement is sometimes found (I) that physical adsorption is essentially nonspecific in nature, particularly when nonpolar gases are used as adsorbates. It will be shown, however, that this is an oversimplification of the process and that specificity is almost as prevalent, although not as obvious, in physical adsorption as in chemisorption. A general review of physical adsorption has been given in this series by de Boer 2), and other specialized topics have been discussed by Kemball (S), HiU (4), and Halsey (S) they may be consulted for the many aspects of the subject not considered in this article. 

The ail viscosity can be found in Table 1.2, Appendix I, where we find that the viscosity at 644 K is about 3.1 X 10 5 kg/m s. The Fuller—Schettler—Giddings equation is proposed for the determination of the diffusion coefficient of nonpolar gases in binary mixtures at... 

For nonpolar gases at high pressures, the correlation of Jossi et al. is preferably used for reduced density between 0.1 and 3 (Jossi et al., 1962 Reid et al., 1988 Perry and Green, 1999) ... 

Interdiffusion of nonpolar gases and also self-diffusion a = 3.882 X 10 4... 

M. Moraldi, J. Borysow, and L. Frommhold. Spectral moments for the collision induced rotovibrational absorption bands of nonpolar gases and mixtures. Phys. Rev., A 36 4700, 1987. 

L. M. Trafton. The pressure induced monochromatic translational absorption coefficients for homopolar and nonpolar gases and gas mixtures with particular application to H2. Astrophys. J., 146 558, 1966. 

For nonpolar gases, the binary diffusion coefficients for internal energy Vj jnti are approximated by the ordinary binary diffusion coefficients Vjk. However, in the case of collisions between polar molecules, where the exchange is energetically resonant, a large correction is necessary of the form [103]... 

While reasonably accurate for the permeation of simple nonpolar gases, this equation is less suit-able for water vapor, so the permeability data quoted for this substance are of qualitative. significance only. 

Accordingly, this probable site of gas solubilization suggests that the much higher solubility of nonpolar gases in micelles than in water ought to be observed in both spherical and rod-shaped... 

Dipole-induced dipole interactions are also important. Nonpolar molecules tend to have their electron clouds attracted (or repelled) by a nearby dipolar molecule oriented with its positive (or negative) end toward the nonpolar species. This induced dipole interacts, on the average, with the dipolar molecule as if it were a permanent dipole. This effect is responsible for the solubility of nonpolar gases such as 02, N2, or C02 in water. 

There are several types of environments on Earth where significant water exists at prevalent low temperatures such that ice and liquid aqueous solutions commonly coexist permafrost, snow, glaciers, lake and river ice, sea ice, and parts of the atmosphere (polar troposphere, global upper troposphere, and stratosphere). In addition, the deep sea floor occurs at temperatures very close to the freezing point of water. For example, temperatures in the oceanic abysses hover around 2°C at a maximum hydrostatic pressure of 1100 bars (10,660 m) in the Mariana Trench (Yayanos, 1995). Table 4.1 summarizes some of these environments. Furthermore, in some permafrost and sea-floor environments, the presence of nonpolar gases under pressure can stabilize a modified form of ice known as gas hydrates even where temperatures are not quite low enough for ordinary ice to form. 

Healy et al. (134) studied experimentally the heats of adsorption of many polar and nonpolar gases on polar and nonpolar surfaces by means of their heats of immersion. It was found that the heat of immersion of rutile on a series of straight-chain compounds was a linear function of the dipole moment of the wetting liquid. In a later article (135)- this work was extended and it is shown that nearly the entire heat effect on immersion of the clean solid surface is due to adsorption of molecules in the first layer. From the slope of the line, giving the values found for the net heat of adsorption as a function of the dipole moments, the average field strength, F, of rutile can be found by means of Eq. (22). The experimental value found by these investigators is... 

The most reliable calorimetric data on the enthalpy of dissolution of various nonpolar gases, the noble gases and hydrocarbons, are collected in Table II. The very small gaseous molecules (helium and neon) were not included. The surface area of the considered molecules, As, have been calculated from the known spatial structure of the molecule and represented either in terms of A2 or the number of contacting water molecules, Nt, assuming that each water molecule occupies an area of about 9 A2 (Hermann, 1972). The direct correlation between the enthalpy of dissolution of a gas in water, A H, and the surface area of the solute molecule, At, or the number of water molecules contacting the solute molecule, Ns, is seen from column flve in Table II. 

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