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Average rate constant

The collision partners may be any molecule present in the reaction mixture, i.e., inert bath gas molecules, but also reactant or product species. The activation k and deactivation krate constants in equation (A3.4.125) therefore represent the effective average rate constants. [Pg.787]

The value of the rate constant can be determined by substituting the rate, the [C3H5O], and the [H+] for an experiment into the rate law and solving for k. Using the data from experiment 1, for example, gives a rate constant of 3.31 X 10 s h The average rate constant for the eight experiments is 3.49 X 10-5 M-i s-i ... [Pg.754]

Thermal initiation of styrene has been shown to be third order in monomer. The average rate constants for third order initiation determined by Hui and Hamielec is k = 105 34 e(,j8iaT) (M V).- "0 The rate constant for formation of the Mayo dimer determined in trapping experiments with nitroxidcs (Scheme 3.63) or acid (Scheme 3.64) as kn = 104 4 (M ls 1)j21 is substantially higher than is... [Pg.109]

Before any chemistry can take place the radical centers of the propagating species must conic into appropriate proximity and it is now generally accepted that the self-reaction of propagating radicals- is a diffusion-controlled process. For this reason there is no single rate constant for termination in radical polymerization. The average rate constant usually quoted is a composite term that depends on the nature of the medium and the chain lengths of the two propagating species. Diffusion mechanisms and other factors that affect the absolute rate constants for termination are discussed in Section 5.2.1.4. [Pg.234]

Figure 8. Plot used to determine average rate constant ratios of the CnH2l+ chain. (C2H4) + indicates only empirical formula but not... Figure 8. Plot used to determine average rate constant ratios of the CnH2l+ chain. (C2H4) + indicates only empirical formula but not...
One may also use the methods of the statistician to determine average rate constants (e.g., the standard unweighted least squares procedure). [Pg.55]

In this case, the thermal average rate constant given by Eq. (3.20) becomes... [Pg.28]

The thermally averaged rate constant is the velocity averaged and can be determined by averaging the velocity... [Pg.233]

The average rate constant in the nonionic pE is, however, considerably higher than all the rate constants in the cationic system, rather than lower. As discussed above, this is due to the effect of ionic strength on the reaction rate and a correction must be made for it if a meaningful comparison of the data is to be made. The dependence of the rate constant k , on the ionic strength (I) is shown in figure 2. Within experimental error,... [Pg.179]

Table 11.2 Average rate constants and number of amide hydrogens in each rate group for H/D exchange of ras-CDP under different Mg concentrations. Measurements were made in 100 mM KCI/50 mM HEPES, 90% D2O, apparent pH of 7.4, T = 21.5 + 0.5 °C. The final [ras-GDP]tot in H/D exchange media was 1.5 pM. EDTA was used to control [Mg +] in solution. Table 11.2 Average rate constants and number of amide hydrogens in each rate group for H/D exchange of ras-CDP under different Mg concentrations. Measurements were made in 100 mM KCI/50 mM HEPES, 90% D2O, apparent pH of 7.4, T = 21.5 + 0.5 °C. The final [ras-GDP]tot in H/D exchange media was 1.5 pM. EDTA was used to control [Mg +] in solution.
Arrhenius plot is done using concentration averaged rate constant against reciprocals of absolute temperatures. The activation energy is found 71. kJ.mol and rate equation is expressed like the next equation. [Pg.124]

Temp. (°C) Initial press, of FCIO2 (mm) Average rate constant (sec"i) Half-life... [Pg.354]

A). When 30 equivalents of ferric ion were added and all imine sites were bound, the average rate constant was determined to be 1.5 x 10 2 cm/s (with an estimated average distance between the electroactive sites and the outer shell of 2.40 A). In the former case, electron transfer had to occur to the topologically central sites. In the latter case, electron transfer could occur to any site, and thus the effective distance required for electron transfer decreased. [Pg.104]

With respect to the consumption of HO, you can also find the corresponding second-order rate constants q. in the literature. For reaction of HO with DOM, an average rate constant h0.Doc =2.5x 104L(mgoc)-1 s-1 can be used (Larson and Zepp, 1988 Brezonik and Fulkerson-Brekken, 1998). For reactions with HCO and CO7-, the rate constants are Ho-,hco3 = 1-0 x 107 M-1 s-1 and H0.C02- = 4.0 x 108 M-1 s-1 (Larson and Zepp, 1988). Insertion of all these rate constants together with Eq. 2 into Eq. 1 yields ... [Pg.663]

Although the common features 1, 2, and 3 above were for certain idealized prepared states, it seems reasonable to expect that the actual prepared state appropriate to a given experiment may be similar enough that these same common features will be exhibited for the microscopic rate constants. These common features of the microscopic rate constant may in turn provide qualitative predictions for the averaged rate constant Arise- These qualitative predictions are expected to be characteristic of intersystem crossing due to a zero-order crossing. [Pg.42]

The rate constant, kZi, in Equation 38 is dependent on the nature of the third body, M. Therefore, an averaged rate constant, 2Jc34,mXm where Xm are mole fractions of components of the reaction mixture, must be used. Equation 38 then becomes,... [Pg.98]

The effect of pH on the hydroxyl radical reaction rate constants was studied in buffered solution at pH = 3.5, 7.0, and 11.0. As the pH increases above 9, the presence of alternate scavenger HOy will react with hydroxyl radicals, and the rate constant is nearly 300 times that of H202. The data for haloben-zenes showed that the reactivity of hydroxyl radical with these derivatives does not vary much among the compounds studied, and an average rate constant of 5.0 x 109 M 1 s 1 could be used for these compounds. [Pg.263]

Single-Vibronic-Level and Thermal Average Rate Constant. 142... [Pg.121]

In the above discussion the single-vibronic-level and thermal average rate constants have only been calculated using the displaced oscillator surfaces. [Pg.146]

There are three types of rate constants appearing in the previous subsection, i.e., WbUiav, the state-to-state rate constant, Wav (or Wbu), the single-vibronic level rate constant, and Wa b (or Wb a), the thermal average rate constant. In the BOA approximation,... [Pg.190]

Eq. (60) indicates that Wa >b(E) can be obtained from the thermal average rate constant with temperature [1 being determined for Eq. (61). [Pg.193]

Neglecting the super-exchange contribution the thermal average rate constant for the singlet-singlet transfer can be expressed as... [Pg.202]

The average rate constant k = 3.85 and the final rate equation is Rate = 3.85 P i2H6PMe2co- he computed rate constant from PROG3 is 4.68 and the calculated value from Table 3-12 is 3.85. The percentage deviation between these values is 17.8%. Figure 3-22 shows plots of partial pressures of B2H6 and Me2CO versus the initial rate. [Pg.189]


See other pages where Average rate constant is mentioned: [Pg.138]    [Pg.467]    [Pg.54]    [Pg.8]    [Pg.60]    [Pg.197]    [Pg.152]    [Pg.209]    [Pg.325]    [Pg.125]    [Pg.169]    [Pg.104]    [Pg.12]    [Pg.401]    [Pg.334]    [Pg.186]    [Pg.194]    [Pg.41]    [Pg.384]    [Pg.388]    [Pg.4]    [Pg.33]    [Pg.384]    [Pg.141]    [Pg.143]   
See also in sourсe #XX -- [ Pg.15 , Pg.411 ]




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Thermal average rate constant

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