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Parachor numbers

G = superficial mass vapor velocity based on the cross-sectional area of the column, Ib/hr-sq ft M = molecular weight, Ib/lb mole N = dimensionless number P = pressure, consistent units [P] = Sugden parachor sg = specific gravity T = temperature, °F U = superficial velocity, ft/hr... [Pg.44]

A small number of physical properties appears to provide more definite information these are molecular refraction, parachor, and (in a more limited way) ultraviolet absorption6. [Pg.487]

Estimation of a with 5.3.1 requires solely the input of pi and parachor. Parachor can be derived from molecular structure with schemes based on group additivity. Exner [4] gives an excellent review and discussion of various group contribution methods for parachor. A very simple method has been developed by McGowan [5] employing only atomic contribution and the number of bonds, A bonds ... [Pg.63]

With this equation a simple approximate determination can be made of

natural mineral oil fractions of not too extreme aromatic character (%Ca < 30%). The above-mentioned correction was obtained by comparing the parachor values of a large number of aromatic mineral oil fractions with those of the corresponding hydrogenated fractions. [Pg.66]

Fig. 61. Determination of the degree of branching in mineral oil fractions from specific refraction, specific parachor and ring-number Rt. Fig. 61. Determination of the degree of branching in mineral oil fractions from specific refraction, specific parachor and ring-number Rt.
Product Result of vacuum distillation Physical constants Specific refraction Specific parachor P Apparent ring-number estimated from (p= 11X A ring... [Pg.69]

Equation 10 generalizes the expression of Erdos (31) applicable to components involving the same functional group. Returning to the constant C in Equation 10, usually the number of carbon atoms does not directly affect the constant. Apparently this effect is corrected by the parachor which changes with the number of carbon atoms. For example, for aromatics in furfural ... [Pg.65]

Some of the earliest techniques for compound selection were essentially visual and as such have considerable appeal compared with the (apparently) more complex statistical and mathematical methods. The first method to be reported came from a study of the relationships between a set of commonly used substituent constants (Craig 1971). The stated purpose of this work was to examine the interdependence of these parameters and, as expected, correlations (see Box 2.1) were found between the hydrophobidty descriptor, %, and a number of bulk parameters such as molecular volume and parachor. Why should interdependence between substituent constants be important There are a number of answers to this question, as discussed further in this book, but for the present it is sufficient to say that interdependence between parameters is required so that clearer, perhaps mechanistic, conclusions might be drawn from correlations. As part of the investigation Craig plotted various parameters together, for example the plot of ct vs. n shown in Fig. 2.2 such plots have... [Pg.35]

The parachor (Pr) is an additive physico-chemical property of a substance related to its molar volume. The value of the parachor is determined by the kind and the number of atoms in a molecule as well as their manner of arrangement and binding. [Pg.200]

From the parachors of a large number of organic compounds, we observe that the contribution of — N02 group on an average, corresponds to 73.6. Thus, the constitution of a nitro group should be given by structure (II). [Pg.102]

More and more publications have reported the physicochemical properties of some ILs, but the overall amount of property data measured by experimental methods are still not fulfilling the requirements for their broad apphcation, especially, due to the lack of data of IL homologues which would be helpful to improve the selection of more appropriate test candidates for different applications. A recently developed technical approach- based on the experimental data of densities and surface tensions of small number of ionic liquids -enables estimation and prediction of density, surface tension, molecular volume, molar volume, parachor, interstice volume, interstice fractions, thermal expansion coefficient, standard entropy, lattice energy and molar enthalpy of vaporization of their homologues. [Pg.4]


See other pages where Parachor numbers is mentioned: [Pg.362]    [Pg.362]    [Pg.67]    [Pg.487]    [Pg.487]    [Pg.14]    [Pg.63]    [Pg.87]    [Pg.65]    [Pg.444]    [Pg.56]    [Pg.225]    [Pg.304]    [Pg.67]    [Pg.5]    [Pg.83]    [Pg.121]    [Pg.365]    [Pg.302]    [Pg.107]    [Pg.148]    [Pg.201]   
See also in sourсe #XX -- [ Pg.366 ]




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