Benzene molecular volume

F = Function of the molecular volume of the solute. Correlations for this parameter are given in Figure 7 as a function of the parameter (j), which is an empirical constant that depends on the solvent characteristics. As points of reference for water, (j) = 1.0 for methanol, (j) = 0.82 and for benzene, (j) = 0.70. The two-film theory is convenient for describing gas-liquid mass transfer where the pollutant solute is considered to be continuously diffusing through the gas and liquid films. 

Table 4 Molecular volume of guests (Vg), host cavity (Vc) and PCcavity in the inclusion compounds of CA with monosubstituted benzenes.

The difference between the nitrogen and benzene micropore volumes is about 20%, that is, much greater than found with the Maxsorb carbons. However, it is not possible to say whether this indicates a true molecular sieving of nitrogen in a proportion of very narrow micropores or whether the density of nitrogen in T5A is even higher than that in the wider micropores of the Maxsorbs. 

In all cases, both permeability and diffusivity of methyl-substituted benzenes vary in an inverse manner with their molecular volumes (as calculated by dividing the molecular weight by density and Avogadro number to yield the volume per molecule). For other penetrants, namely, anisole, nitrobenzene, chlorobenzene, -dichlorobenzene and bromobenzene, the volume per molecule varies in the range 17-19. However, their diffusion trends are quite different. For instance, though nitrobenzene and chlorobenzene... 

For benzene at 25°C this becomes AU = 33,900 - 8.314 (298) = 31,400 J mol". The molar volume of a compound is given by V° = (molecular weight)/ (density). For benzene at 25°C, this becomes V° = 78.0/0.879 = 88.7 cm mol". Tlie cohesive energy density is simply the ratio AUy/V°, but in evaluating this numerically, the question of units arises. By convention, these are usually expressed in calories per cubic centimeter, so we write... 

Other than fuel, the largest volume appHcation for hexane is in extraction of oil from seeds, eg, soybeans, cottonseed, safflower seed, peanuts, rapeseed, etc. Hexane has been found ideal for these appHcations because of its high solvency for oil, low boiling point, and low cost. Its narrow boiling range minimises losses, and its low benzene content minimises toxicity. These same properties also make hexane a desirable solvent and reaction medium in the manufacture of polyolefins, synthetic mbbers, and some pharmaceuticals. The solvent serves as catalyst carrier and, in some systems, assists in molecular weight regulation by precipitation of the polymer as it reaches a certain molecular size. However, most solution polymerization processes are fairly old it is likely that those processes will be replaced by more efficient nonsolvent processes in time. 

In order to minimize confusion, only the curves representing the smoothed results are shown for squalene-benzene, polyisoprene-ben-zene, and rubber-benzene. Calorimetric methods were applied to those polymers of comparatively low molecular weight temperature coefficients of the activity were used for the rubber-benzene mixtures. The ratio of the heat of dilution to the square of the volume fraction t 2, which is plotted against in Fig. 112, should be independent of the concentration according to the treatment of interactions... 

---