Rate coefficient, average

Some typical results are given in Table 21 and Table 22 shows the average rate coefficients (in some cases corrected for temperature and solvent differences) obtained for a range of compounds in carbon tetrachloride97. 

AVERAGE RATE COEFFICIENTS (1 02/c3.j) FOR REACTION OF ArH WITH PhCOCl IN PhN02 CATALYSED BY AICI3 AT 25 C342, 412... 

The intercept, 6.5 kcal.mole leads to a value of 13.0 kcal.mole for the (average) AG of the various phenanthroline Fe(II)-Fe(lII) exchanges. Such a AG , 2 value corresponds to an average rate coefficient, /c2,2, of 2x 10 l.mole T... 

When potential surfaces are available, quasiclassical trajectory calculations (first introduced by Karplus, et al.496) become possible. Such calculations are the theorist s analogue of experiments and have been quite successful in simulating molecular reactive collisions.497 Opacity functions, excitation functions, and thermally averaged rate coefficients may be computed using such treatments. Since initial conditions may be varied in these calculations, state-to-state cross sections can be obtained, and problems such as vibrational specificity in the energy release of an exoergic reaction and vibrational selectivity in the energy requirement of an endo-... 

The average rate coefficient for the propagation of the A-monomer, is given by... 

The average rate coefficient for radical desorption, k, is defined using the equations... 

The average rate coefficient for radical termination in the particle phase, fc(p> is defined by... 

The polymerization of 2-methyl-2-oxazoline is another example of the parallel growth of macroions and covalent macromolecules X The averaged rate coefficients of propagation kp (including kj, and k ) for various anions, namely Cl , Br ,, and OTos (Tos = S02C H4CH3-p) were measured in CD3CN at 40 °C and found to be equal to (x 10, in mole 1 s ) 0.03,... 

Finally, the thermally averaged rate coefficients of the QCT and GCE models are compared with rates computed using recommended Arrhenius parameters and experimental data " " " in Fig. 16. At all temperatures, the agreement between the QCT and GCE results is excellent. Note that the QCT analysis predicts a significantly higher rate than that of Park at temperatures above 5000 K. 

In a similar way an average rate coefficient for molecules with total energy E may be obtained and is found to be... 

So far our discussion has focused on the measurement of thermal rate coefficients for a number of different classes of reactions involved with low temperature combustion. A significant proportion of the kinetics community is interested in looking beyond thermally averaged rate coefficients k T)) towards quantum state specific data the rate coefficient for reagents in the quantum state vj. The two quantities are related via equation (2.71)... 

The propagation reaction is described in terms of an average rate coefficient, k, and the polymer radical concentration, [R ]. The value of k is very large, 10 -10" dm moP s and is independent of chain length. This is the reaction that consumes monomer and grows the polymer chain. 

The corresponding rate coefficients for the formation of a specified final product, B7.,fp and v.fp, may be derived by replacing rAn in Formulae 23 and 24 by the measured number of molecules of final product formed, or by introducing into those formulae a stoichiometric factor < s that specifies the number of product molecules known to be formed per molecule of the parent species decomposed or reacted. Bz and rjz are thus average rate coefficients for the inter-electrode space, and they are measures of the difference between the rate of synthesis of the final product and the sum of the rates of loss of that species by being decomposed in the discharge and by other processes. 

Since the spatial distribution of OH and temperature favors a destruction of methane in the lower troposphere, an average rate coefficient of 5x 10-15 cm3/molecules may be applied, corresponding to an effective temperature of 280 K. With ii(OH) = 5 x 10s molecules/cm3, one then obtains OH = 300 Tg/yr. Crutzen and Fishman (1977) used a more detailed integration procedure to obtain SOH = 334 Tg/yr. 

T = j For a daily mean estimate of the photochemical conversion rate according to Eq. (4.134), it is useful to determine an average rate coefficient as ... 

The form of Eq. (47) is analogous to the homopolymerization rate expression [Eq. (10)], with a copolymer-averaged rate coefficient for propagation (generalized for a system with Nmon different monomers) defined in Eq. (50). 

In the case of copolymerization, the copolymer-averaged rate coefficient for propagation shonld be used instead of k and [A/]p represents the total monomer concentration in the polymer particles [11]. 

To the extent that K(t) is constant throu out a time interval that is comparable to then the correct time dependent rate expression can be replaced by an approximate quasi steady state analog. Even in the absence of a true steady state, certain features of an average rate coefficient formulation will continue to be applicable (23.25.27,51,32). This conclusion is insensitive to the present assumptions concerning nonreactive scattering. It would be strengthened by the inclusion of a more realistic representation of the energy dependent nonreactive cross section, since a relative reactivity increase would lead to ccmipression of the time and ranges sampled by nonthermal reaction. 

The pseudo-homopolymerization approach [30, 52] can be used to calculate the average rate coefficient (kjes) for desorption of free radicals out of the latex particles in emulsion copolymerization systems. For a binary polymerization system comprising comonomers A and B, k es can be expressed as... 

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