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Boltzmann constant numerical value

The quantity that appears in the argument of the exponential at the numerator is the molar free enthalpy of reaction of the reaction intermediate that is identified with the molar activation energy Eg and with the opposite of the standard chemical potential pf. The pre-exponential term is the intrinsic rate constant /(° that is equal to the scaling chmical potential ju divided by the Avogadro constant and by the Planck constant h or what amounts to the same, by dividing numerator and denominator by to keep only the Boltzmann constant (the values of these constants are given in Appendix 2). [Pg.88]

Bollworm/budworm complex, 5 9 Bolometers, 19 143-144 Bolton-Hunter reagent, 21 274 Boltzmann distribution, 14 657 26 1035 Boltzmann s constant, 26 1035 numerical value of, 24 434 Boltzmann s law, 14 662 Bolzano magnesium manufacturing process, 15 342... [Pg.112]

Let us now put all of this together to obtain a numerical value of the rate constant k for the chemical reaction. Note that chemists always use the symbol k for the rate constant. Elsewhere in this chapter and in other chapters, we also use k for Boltzmann s constant. Whenever there is a possibility of confusion, we will use kB for Boltzmann s constant. The rate constant is defined by the relation... [Pg.121]

Eq. (3.9) arises from the absolute rate theory and can be expressed in the following logarithmic form, using the numeric values of the Boltzmann constant k, the gas constant R, the Planck constant h, and loge [108]. [Pg.128]

In statistical mechanics the Boltzmann constant, /cB, with dimensions of energy per degree is included in expressions so that the temperatures can be given in degrees Kelvin. The numerical values of nuclear temperatures in Kelvin are very large, for example 109 K, so the product of /cB and T is usually quoted in energy units (MeV) and the Boltzmann factor is often not written explicitly. [Pg.167]

Thus, at high I, the pair population is a considerably smaller fraction of the total OH population than the initial fraction given by a Boltzmann distribution at the flame temperature. For example, for the nominal values of 14 and 0.4 A for Oq and Oy, the infinite-intensity fraction is < 1% of the total while the zero-intensity value is 4%. This result is generally valid for the entire range of parameters inserted into the model, which represent physically realistic energy transfer rates. However, the precise numerical values depend sensitively on the actual parameters inserted. These facts form the central conclusions of this study (4). A steady state model with no dummy level and a different set of rate constants and level structure (5) shows some similar features. [Pg.144]

Here is a numerical constant called the Boltzmann constant. It is not easy to have an intuition about the number of microstates of a system, so this equation is hard to use directly at this stage of your study of chemistry. We ll soon see that we won t need to use it. It is important, however, to realize that as a system becomes more random, the value of Q. will increase. So, the entropy of a system increases as the system moves toward more random distributions of the particles it contains because such randomness increases the number of microstates. [Pg.397]

The Boltzmann constant fe, which originated in (11-14), has not yet been finally identified with R/L (see equation 11 50). However if it is assumed for the moment that this is the case, it is readily shown, by inserting numerical values, that the coefficient g in (12-45) is exceedingly small for all reasonable values of T and a. It follows that the first term (i.e. 1) in the summation is practically unity,... [Pg.375]

On substituting numerical values for the Planck and Boltzmann constants (h=6.626x 10" ergs and ka= 1.381 x 10 erg AT" ) one obtains for the pre-exponential factor at 25 C (kj T/h)=6.2Ax lO s . This is the frequency of vibration and thus has the units of a first order rate constant. If (/ = 0 this frequency determines the maximum rate with which a reaction can occur. In the case of a second, or higher, order reaction a factor to account for the colUsion frequency, has to be added to the basic equation. [Pg.243]

The Planck formula suggests how to find numerical values of constants in Stefan-Boltzmann and Wien laws. In particular on integration of Kirchhoff s law on the whole frequency range one can arrive at the Stefan-Boltzmann formula. The constant in Wien s law b can be found by derivation of the Kirchhoff s function on frequency and equalizing it to zero. We hope that readers can carry out these calculations themselves. [Pg.406]

We define quantitative scientific knowledge as the combination of numerical data and formulas. A quantity can be a geometrical quantity like area or volume, or a physical quantity like mass or viscosity. A geometrical quantity is a variable which depends on the geometrical shape under consideration. Physical quantities can be categorised into constant properties and variables. Physical constants are the universal constants of nature, such as Boltzmann s constant (k = 1.380658 10-23/A-1). Physical properties are quantities which hold different values for different substances (or elements) in different states, for example, the Critical Volume (m3 mo/-1) 72.5 10-6 of Ammonia. The physical constants and physical properties are held in a database. Physical variables (sometimes called state variables) are independent variables which describe the state of a physical system, such as temperature (T) or pressure (P). The variables (including geometric values) are either specified by a user or computed by the system. [Pg.321]

In order to determine the values of the constants ci and C2, these equations must be matched to a solution valid in the outer region (i.e., f < 5). We followed Russel and Sdgter s approach in calculating f in the outer region numerically and matched f to the Fuoss solution for y > 5 to obtain a complete solution of the full nonlinear Poisson-Boltzmann equation for a arbitrary surface charge density... [Pg.159]


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See also in sourсe #XX -- [ Pg.51 ]




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