Literature values

Along with the curve fitting process, TableCurve also calculates the area under the curve. According to the previous discussion, this is the entropy of the test substance, lead. To find the integral, click on the numeric at the left of the desktop and find 65.06 as the area under the curve over the range of x. The literature value depends slightly on the source one value (CRC Handbook of Chemistry and Physics) is 64.8 J K mol. ... 

The fact that good correlations are observed with d" rather than with a, is indicative of a strong infiuence of the substituent through a direct resonance interaction with a positive charge in the reacting system. The p-values are positive, which is expected for substituted dienophiles in a normal electron demand Diels-Alder reaction. Furthermore, the p-values do not exceed unity and are not significantly different from literature values reported for the uncatalysed reaction. It is tempting to... 

This relationship with a = 1 was first proposed by Staudinger, but in this more general form it is known as the Mark-Houwink equation. The constants k and a are called the Mark-Houwink coefficients for a system. The numerical values of these constants depend on both the nature of the polymer and the nature of the solvent, as well as the temperature. Extensive tabulations of k and a are available Table 9.2 shows a few examples. Note that the units of k are the same as those of [r ], and hence literature values of k can show the same diversity of units as C2, the polymer concentration. 

Considerable effort has been devoted to the NMR study of pyrazolines. The results shown in Table 13 represent a minute part of the literature values, and more can be found in (B-73NMR165). 

The REE values obtained for the U.S.G.S. standards by this method compare well with the literature values obtained by NAA, MS and other methods. Einear calibration curves in the range of about 0 to 200 956 g/g are obtained and detection limits in the range of 0.06 to 0.04 956 /g are achieved. 

A large number of substances are ionisable in aqueous solutions and a knowledge of their ionisation constants, stated as pK (pKa) values, can be of importance not only in their purification but also in their reactivity. Literature values of the pK s have been inserted for ionisable substances, and where values could not be found they were estimated (pKesi)- The estimates are usually so close to the true values as not to affect the purification process or the reactivity seriously. The book will thus be a good compilation of pK values for ionisable substances. 

Literature values for 0.6 factor exponents can be found in References 3 and 32. 

Hilado and Clark report difficult-to-find autoignition temperatures while eliminating apparent discrepancies in literature values. Table 1 shows their compilation. 

The ratio of p JPmin be as high as 1.52 depending on the material. Consequently, when bulk densities are reported it is important to note whether the value was determined under loose or tapped conditions, along with the mean particle size. Most literature values report an average bulk density that is representative of the material most often handled. Loose solids may be broadly characterized according to their bulk densities ... 

The crystal growth rates can be directly determined from the second and third moment as described above. The calculated rates for calcium oxalate here are in the range 0.75 x 10 to 4.7 x 10 m/s. Literature values for the growth rate of calcium oxalate monohydrate vary considerably 1.08 x 10 m/s (Kavanagh, 1992), 3.4 X 10 to 5.0 x 10 m/s (Garside etal., 1982) and 2.8 x lO to 1.11 X 10 m/s (Nielsen and Toft, 1984). The values obtained from the experiments are therefore within the range of the literature data. It should be borne in... 

Nueleation rates, whieh are ealeulated from the growth rates and the population densities at L 0 eover a range from 5.6 x 10 to 2.8 x 10" m s . Literature values for nueleation rates of ealeium oxalate monohydrate are rare Garside etal. (1982) found nueleation rates from 2.78 x lO to 8.33 x lO m s at 37 °C and 0.001 M feed eoneentration, and those ealeulated from the data of Brown etal. (1990) are between 2.78 x 10" and 2.7 x 10 m s , also at 37°C. 

By contrast with the water-soluble sulfides of Groups 1 and 2, the corresponding heavy metal sulfides of Groups 11 and 12 are amongst the least-soluble compounds known. Literature values are often wildly discordant, and care should be taken in interpreting the data. Thus, for black HgS the most acceptable value of the solubility product [Hg +][S ] is 10- mol2l-2, i.e. 

The second estimate compares better with the literature value of -7,700 cal/g-mole. 

Heating phenyl isocyanate or its derivatives in the presence of Lewis acids reportedly gives diazocinediones 42 however, the assignment of structure 2 to the product from phenyl isocyanate is questionable as the melting point (mp 279-280 C)42 differs markedly from the generally agreed literature value (mp 334 C)43 (see also Section 1.5.1.2.3.). 

Note that the value of Te is dependent on the monomer concentration. In the literature, values of Tc may be quoted for [M] = 1.0 M, for [M] = [ M et or for bulk monomer. Tints care must be taken to note the monomer concentration when comparing values of TK. One problem with using the above method to calculate fc. c or l c, is the paucity of data on ASp. A further complication is that literature values of AHP show variation of +2 kJ mol1 which may in part reflect medium effects. 77 This "error" in A//p corresponds to a significant uncertainty in Tc. 

Methods for measurement of kp have been reviewed by Stickler,340 41 van Herk Vl and more recently by Beuermann and Buback.343 A largely non critical summary of values of kp and k, obtained by various methods appears in the Polymer Handbook.344 Literature values of kp for a given monomer may span two or more orders of magnitude. The data and methods of measurement have heen critically assessed by IUPAC working parties"45"01 and reliable values for most common monomers are now available. 43 The wide variation in values of kp (and k,) obtained from various studies docs not reflect experimental error but differences in data interpretation and the dependence of kinetic parameters on chain length and polymerization conditions. 

These issues are thought to account for much of the scatter apparent in literature values of t.3 16 PLP and related methods yield absolute values of kp directly (the methods used for extracting kp arc discussed in Section 4.5.2). These values may be combined with either kp kx or k k, to give k,. 

The rate constants for chain transfer and propagation may well have a different dependence on temperature (i.e. the two reactions may have different activation parameters) and, as a consequence, transfer constants are temperature dependent. The temperature dependence of Clr has not been determined for most transfer agents. Care must therefore he taken when using literature values of Clr if the reaction conditions are different from those employed for the measurement of Ctr. For cases where the transfer constant is close to 1.0, it is sometimes possible to choose a reaction temperature such that the transfer constant is 1.0 and thus obtain ideal behavior. 3... 

A proof for the sulfinic acids in these reactions is found in the study of the pH dependence of the conductivity signal. This study can give in some cases the pKa of the acid formed (this is true only for some cases, since the conductivity measurements are limited to pH < 2). It was found, for example, that for DMSO, pKa is 2.35 compared to the literature value of 2.28. 

It is also worth emphasizing the excellent agreement in the initial dipole moment P° values for Na/Pt computed in ref. 1 with literature values for Na/Pt(lll).9,13 This agreement shows that Na introduced on the catalyst surface via f3"-Al2C>3 to induce NEMCA is in the same binding state with Na... 

Figure 9.9 shows typical galvanostatic transients. Computed dipole moments of Na/Pt are again in reasonable agreement with the literature value ofl.75xl0 29 C m (5.3 Debye)13. The promotion indexP is up to 250 under... 

Based on industrial monitoring data Based on literature values (36)... 

Values for degassed solutions. "With one atmosphere cyclohexane. N,N-dlmethyl-l-naphthylamlne. Trans-1,6-dlphenyl-l, 3,5-hexatrlene. Average of 13 literature values (see Ref. 50). Values from many authors agree for a single exponential, but there appear to be two exponentials that show wavelength dependence. 2,5-Dlphenyloxazole. "p-Bls(2-phenylozazolyl)benzene. Decay time dependent on Cl or I" concentration. 

The reaction rates in Equation (5.17) are positive and apply to the reaction. That is, they are the rates of production of (possibly hypothetical) components having stoichiometric coefficients of -bl. Similarly, the heats of reaction are per mole of the same component. Some care is needed in using literature values. See Section 7.2.1. 

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