Hexane data

Fig. 16 EM-profile for intramolecular fluorescence quenching in Me2N(CH2)m NMe2 in hexane. (Data from Halpern et al., 1979)...

Fig. 10. Dependence of solvent strength of B- or C-solvent (e) on its coverage of the surface (0) for amino-silica. Mixtures A/B or A/C, where A is hexane [data taken from Snyder and Schunk (/7)] O, CCl , CHjCla V, CHClatQ, ethyl acetate , tetrahydro-furan.

Results of pyrolysis of propane, n-butane, and n-hexane at a wide range of temperatures and conversions, including the range of commercial operation, are presented. Extensive product inhibition is evident in all cases. The rates of decomposition can be characterized by two pseudo energies of activation E, calculated by comparing data at constant decomposition, variable time and temperature, and E (always less than E) at constant time, variable decomposition and temperature. Both E and E are relatively constant over the conversion range studied. Near atmospheric pressure data fit the equation X = exp —sl0 [1 + 1-3 (Nc — 2)] t1/re — E /RT where X = fraction feed paraffin undecomposed, Nc = carbon number of feed paraffin, r = E/E = 1.68, t = reaction time (seconds), T = reaction temperature (K), a0 = 2.85 109 (from propane data) or 2.66 109 (better to n-butane and n-hexane data), and E = 46.0 kcal/ mol. 

Figure 11. Fraction of n-butane or n-hexane converted vs. r = t/t1 (1 atm data only, t, calc for best fit to butane hexane data). (O) n-butane, 1 atm, set 1 (Q) n-butane, 1 atm, set 2 ((pj n-butane, 1 atm, set 3 (0) n-butane, 1 atm, set 4 ( ) n-hexane, 1 atm, set 1 ( ) n-hexane, 1 atm, set 2 t = t0 k calculated by Equation 13 fitted to n-butane and n-hexane data.

Will the Temkin isotherm fit the n-hexane data shown in Prob. 8-1 ... 

Fig. 43. Plots of kgbs versus [Y] for the reaction of tro s-(Pt(PPr3X NHEt2Cl2] with NHEt2 in methanol and in hexane. Data from T.P. Cheeseman, A.L. Odell and H.A. Raethel. Chem. Commun., 1496(1968).

Liquid-liquid equilibrium data of polyethylene in cyclohexane and n-hexane Data extract from Landolt-Bornstein VIII/6D3 Polymers, Polymer Solutions, Physical Properties and their Relations I (Thermodynamic Properties Equilibria of Ternary Polymer Solutions) ... 

Data calculated at 7 days of oxidation for hydropa"oxides and 8 days for hexanal data... 

More recent studies determined hexanal and other volatile compounds by headspace gas chromatography (HS-GC) to measure lipid oxidation in meat. Although hexanal data may sometimes be in agreement with the results of the non-specific TEA method, the sensitive HS-GC method is more desirable because it determines specific decomposition products of lipid hydroperoxides. The same factors that influence lipid oxidation in meat such as pH, metal catalysts and antioxidants also affect and confound the interpretation of the results of the colorimetric TEA method. The TEA method is, therefore, not recommended to determine oxidation of meat and other complex foods because the degree to which non-lipid oxidation and degradation products, including browning reaction products, contribute to the TEA color remains unclear. 

Figure 5 shows the isothermal data of Edwards (1962) for n-hexane and nitroethane. This system also exhibits positive deviations from Raoult s law however, these deviations are much larger than those shown in Figure 4. At 45°C the mixture shown in Figure 5 is only 15° above its critical solution temperature. Again, representation with the UNIQUAC equation is excellent.

It is difficult to judge the accuracy of these methods because data are scarce. Table 4.9 compares the values obtained by different weighting methods with experimental values for a mixture of n-hexane-n-hexadecane at 25°C. The ASTM method shows results very close to those obtained experimentally. 

Still another manifestation of mixed-film formation is the absorption of organic vapors by films. Stearic acid monolayers strongly absorb hexane up to a limiting ratio of 1 1 [272], and data reminiscent of adsorption isotherms for gases on solids are obtained, with the surface density of the monolayer constituting an added variable. 

We will generate the energies for the carbon-hydrogen bond /fen and the carbon-carbon single bond Hix using the five linear alkanes from ethane through hexane as the five-member data base. The equation to be used is... 

Gestodene Gestodene (54), along with norgestimate and desogestrel, are the progestin components of the third-generation oral contraceptives (see Contraceptives). It may be crystallised from hexane/acetone (81) or ethyl acetate (82), and its crystal stmcture (83) and other spectral data have been reported (84). 

Norethindrone may be recrystakhed from ethyl acetate (111). It is soluble in acetone, chloroform, dioxane, ethanol, and pyridine slightly soluble in ether, and insoluble in water (112,113). Its crystal stmcture has been reported (114), and extensive analytical and spectral data have been compiled (115). Norethindrone acetate can be recrystakhed from methylene chloride/hexane (111). It is soluble in acetone, chloroform, dioxane, ethanol, and ether, and insoluble in water (112). Data for identification have been reported (113). The preparation of norethindrone (28) has been described (see Fig. 5). Norethindrone acetate (80) is prepared by the acylation of norethindrone. Norethindrone esters have been described ie, norethindrone, an appropriate acid, and trifiuoroacetic anhydride have been shown to provide a wide variety of norethindrone esters including the acetate (80) and enanthate (81) (116). 

As discussed in Sec. 4, the icomplex function of temperature, pressure, and equilibrium vapor- and hquid-phase compositions. However, for mixtures of compounds of similar molecular structure and size, the K value depends mainly on temperature and pressure. For example, several major graphical ilight-hydrocarbon systems. The easiest to use are the DePriester charts [Chem. Eng. Prog. Symp. Ser 7, 49, 1 (1953)], which cover 12 hydrocarbons (methane, ethylene, ethane, propylene, propane, isobutane, isobutylene, /i-butane, isopentane, /1-pentane, /i-hexane, and /i-heptane). These charts are a simplification of the Kellogg charts [Liquid-Vapor Equilibiia in Mixtures of Light Hydrocarbons, MWK Equilibnum Con.stants, Polyco Data, (1950)] and include additional experimental data. The Kellogg charts, and hence the DePriester charts, are based primarily on the Benedict-Webb-Rubin equation of state [Chem. Eng. Prog., 47,419 (1951) 47, 449 (1951)], which can represent both the liquid and the vapor phases and can predict K values quite accurately when the equation constants are available for the components in question. 

FIG. 13-20 Liqi lid-phase activity coefficients for an ethanol-n-hexane system, [Henleij and Seader, Eqiiilihriiim-Stage Separation Operations in Chemical Engineering, Wileif, New York, 1931 data of Si nor and Weher, J, Chem, Eng, Data, 5, 243-247 (I960).]... 

Efficiency data for a representative structured packing at two column diameters are shown in Fig. 14-74. The Max-Pak packing has a surface area of 246 m /m (7.5 ft /fE). The same test mixture (cyclo-hexane//i-heptane) and operating pressure was used for both tests. It would appear that column diameter does not have an influence in this range of values (0.43 to 1.2 m). 

Tbe partial results are shown in Figure 2-6.2.1. Tbe ranges of ignitable concentrations are superimposed on a spark ignition energy curve for bexane in air calculated from data in [56]. Both data sets are assumed to be characteristic ofn-hexane, unbiased by the presence of methylcyclopentane or hexane isomers (dimethylbutanes and methylpentanes). 

Fig. 6. Optical density vs wavelength for Ceo in hexane solution. The optical density vs wavelength data for long wavelengths are shown on an expanded scale [67].

Equation (16) was tested against some data obtained for (R) 4-phenyl-2-oxazolidinone using a range of mixtures of ethanol, acetonitrile and -hexane as the mobile phase. The column chosen was similar to that previously used for the separation of the 4-phenyl-2-oxazolidinone which was 25 cm long, 4.6 mm I.D. packed with 5 mm silica particles bonded with the stationary phase Vancomycin. The results obtained are shown in Table 1 and this is the data used in subsequent computer calculations. 

C. In their first series of experiments, six data sets were obtained for (H) and (u), employing six solvent mixtures, each exhibiting different diffusivities for the two solutes. This served two purposes as not only were there six different data sets with which the dispersion equations could be tested, but the coefficients in those equations supported by the data sets could be subsequently correlated with solute diffusivity. The solvents employed were approximately 5%v/v ethyl acetate in n-pentane, n-hexane, n-heptane, -octane, -nonane and n-decane. The solutes used were benzyl acetate and hexamethylbenzene. The diffusivity of each solute in each solvent mixture was determined in the manner of Katz et al. [3] and the values obtained are included... 

The results obtained were probably as accurate and precise as any available and, consequently, were unique at the time of publication and probably unique even today. Data were reported for different columns, different mobile phases, packings of different particle size and for different solutes. Consequently, such data can be used in many ways to evaluate existing equations and also any developed in the future. For this reason, the full data are reproduced in Tables 1 and 2 in Appendix 1. It should be noted that in the curve fitting procedure, the true linear velocity calculated using the retention time of the totally excluded solute was employed. An example of an HETP curve obtained for benzyl acetate using 4.86%v/v ethyl acetate in hexane as the mobile phase and fitted to the Van Deemter equation is shown in Figure 1. 

The solvent used was 5 %v/v ethyl acetate in n-hexane at a flow rate of 0.5 ml/min. Each solute was dissolved in the mobile phase at a concentration appropriate to its extinction coefficient. Each determination was carried out in triplicate and, if any individual measurement differed by more than 3% from either or both replicates, then further replicate samples were injected. All peaks were symmetrical (i.e., the asymmetry ratio was less than 1.1). The efficiency of each solute peak was taken as four times the square of the ratio of the retention time in seconds to the peak width in seconds measured at 0.6065 of the peak height. The diffusivities obtained for 69 different solutes are included with other physical and chromatographic properties in table 1. The diffusivity values are included here as they can be useful in many theoretical studies and there is a dearth of such data available in the literature (particularly for the type of solutes and solvents commonly used in LC separations). 

Table 1. Physical and Chromatographic Data for 70 Solutes in 5 %v/v Ethyl Acetate in n-Hexane...

As the alkaloid was extracted with hexane, acetone, and ethanol, subjected to column chromatography, acidified (AcOH) and then neutralized (NaOH), the cationic form was formulated as a hydroxide salt. However, only two OH groups were detectable on H NMR spectroscopy. Only slight differences were found in the UV spectra taken in methanol [kmax (loge) = 218 (4.68), 302 (4.39), 394 (4.08) nm] and methanol+NaOH [T-max (loge) = 228 (4.66), 310 (4.39) nm]. Three tautomeric forms can be formulated which are shown in Scheme 42. Two of them possess the isoquinolium-7-olate moiety. The H NMR data are presented in Table IV. They indeed unambiguously resemble the cationic species 112. 

Decreases with increasing wettability of liquid on plate surface. Kerosene, hexane, carbon tetrachloride, butyl alcohol, glycerine-water mixtures all wet the test plates better than pure water. The critical tray stability data of Hunt et al., [33] is given in Table 8-21 for air-water, and hence the velocities for other systems that wet the tray better than water should be somewhat lower than those tabulated. The data of Zenz [78] are somewhat higher than these tabulated values by 10-60%. 

Structure of luciferin (Ohtsuka et al., 1976). The luciferin of Diplocardia longa is a colorless liquid, and fairly stable at room temperature. It is soluble in polar organic solvents (methanol, ethanol, acetone, and methyl acetate) but insoluble in nonpolar solvents like hexane and carbon tetrachloride. Based on the chemical properties and spectroscopic data, the following chemical structure was assigned to the luciferin. 

The ratio of hydrocarbon products, 1-hexane and methylcyclopentane, was determined. These data, obtained by varying the concentrations of chromium(II), could be used to evaluate fco11 The equation is... 

A gas chromatographic method is described in this work for the analysis of tetradecane-l,4-sultone (C14 5-sultone) and the combination of 2-chloro-tetradecane-l,3-sultone (C14 2-chloro-y-sultone) and l-tetradecene-l,3-sultone (C14 unsaturated y-sultone) in neutral oils isolated from alkenesulfonate. Samples of the neutral oil are diluted in hexane and injected directly into the gas chromatograph. Quantitative data are obtained by comparison to known amounts of the respective sultones. Through the use of silica gel column chromatography followed by GC of collected fractions, separation and individual quantitation of the 2-chlorotetradecane-l,3-sultone and l-tetradecene-l,3-sultone can be obtained. 

The heat of dissociation in hexane solution of lithium polyisoprene, erroneously assumed to be dimeric, was reported in a 1984 review 71) to be 154.7 KJ/mole. This value, taken from the paperl05> published in 1964 by one of its authors, was based on a viscometric study. The reported viscometric data were shown i06) to yield greatly divergent AH values, depending on what value of a, the exponent relating the viscosity p of a concentrated polymer solution to DPW of the polymer (q DP ), is used in calculation. As shown by a recent compilation 1071 the experimental a values vary from 3.3 to 3.5, and another recent paper 108) reports its variation from 3.14 to 4. Even a minute variation of oe results in an enormous change of the computed AH, namely from 104.5 KJ/mole for oe = 3.38 to 209 KJ/mole for oe = 3.42. Hence, the AH = 154.7 KJ/mole, computed for a = 3.40, is meaningless. For the same reasons the value of 99.5 KJ/mole for the dissociation of the dimeric lithium polystyrene reported in the same review and obtained by the viscometric procedure is without foundation. 

Engberts [3e, 9] has extensively investigated the Diels Alder reaction in aqueous medium. Recently Engberts and colleagues reported [9c] a kinetic study of a Diels Alder reaction of N-alkyl maleimides with cyclopentadiene, 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene in different solvents. The reaction rates of the cycloadditions with the open-chain diene relative to w-hexane are reported in Table 6.3. The aqueous medium greatly accelerates the Diels Alder reaction and the acceleration increases as the hydrophobic character of the alkyl group of the dienophile increases. These and other kinetic data [3e, 9], along with the observation that the intramolecular Diels-Alder reaction is also accelerated in... 

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