Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Equilibria explicit equations

IF BINARY SYSTEM CONTAINS NO ORGANIC ACIDS. THE SECOND VIRTAL coefficients ARE USED IN A VOLUME EXPLICIT EQUATION OF STATE TO CALCULATE THE FUGACITY COEFFICIENTS. FOR ORGANIC ACIDS FUGACITY COEFFICIENTS ARE PREDICTED FROM THE CHEMICAL THEORY FOR NQN-IOEALITY WITH EQUILIBRIUM CONSTANTS OBTAINED from METASTABLE. BOUND. ANO CHEMICAL CONTRIBUTIONS TO THE SECOND VIRIAL COEFFICIENTS. [Pg.266]

Although Eq. (10.50) is still plagued by remnants of the Taylor series expansion about the equilibrium point in the form of the factor (dn/dc2)o, we are now in a position to evaluate the latter quantity explicitly. Equation (8.87) gives an expression for the equilibrium osmotic pressure as a function of concentration n = RT(c2/M + Bc2 + ) Therefore... [Pg.685]

The thermodynamic theory of equilibrium was first stated, in a general way, by Horstmann in 1873 (cf. 50), who also obtained explicit equations of equilibrium in the case where it is established in a gas, and showed that these were in agreement with the data available at that time, and with his own experiments. [Pg.324]

Since Eqs. (5) and (6) are not restricted to the vapor phase, they can, in principle, be used to calculate fugacities of components in the liquid phase as well. Such calculations can be performed provided we assume the validity of an equation of state for a density range starting at zero density and terminating at the liquid density of interest. That is, if we have a pressure-explicit equation of state which holds for mixtures in both vapor and liquid phases, then we can use Eq. (6) to solve completely the equations of equilibrium without explicitly resorting to the auxiliary-functions activity, standard-state fugacity, and partial molar volume. Such a procedure was discussed many years ago by van der Waals and, more recently, it has been reduced to practice by Benedict and co-workers (B4). [Pg.171]

Typical representations of the way that the two differing equilibrium relationships can interact are shown in Fig. 3.33, and it is assumed that the equilibria can be correlated by appropriate, explicit equation forms. [Pg.170]

For such a simple equilibrium system, there are explicit equations that are relatively easy to derive. [Pg.41]

As a result, it was obtained an analytical expression of the reaction rate in terms of hypergeometric series with no classical simplifications about the "limiting step" or the "vicinity of the equilibrium". The obtained explicit equation, "four-term equation", can be presented as follows in the Equation (77) ... [Pg.48]

Conceptually, the simplest method for solving phase-equilibrium problems is the phi-phi method, but computationally it is usually more complicated than other methods. The conceptual simplifications arise in part because no decisions need to be made about reference states the reference state is the ideal gas and the choice of the ideal-gas reference is implicit in choosing to work with fugacity coefficients. Usually, the same pressure-explicit equation of state is used for all components in all phases, for this produces consistency in the results and helps in organizing the calculations. (The same calculations are to be done for all components in all phases, and therefore computer programs can be structured in obvious modular forms.) However, this need not be done different equations of states can be used for different phases. [Pg.422]

In Fig. 2.7 the distribution remains symmetrical. The initial fluctuation enhancement and the subsequent drift dominated development of the bimodal distribution into equilibrium can be observed. In Fig. 2.8 the first stages of the development are the same as in Fig. 2.7. In accordance to the asymmetric initial distribution, however, it comes to a bimodal distribution with peaks of differing significance. The final development into the symmetrical stationary distribution is fluctuation dominated and extremely slow. Inserting the explicit equations (2.121,123,131) into (2.116) the transition time for collective opinion change is obtained as... [Pg.49]

To solve for ka and kd explicitly, we need one more equation. We can get this from the consideration of an equilibrium condition. When the concentration on the surface of the adsorbent is no longer changing, then rates of adsorption and desorption are equal. From thiswefind ... [Pg.259]

For adsorbates out of local equilibrium, an analytic approach to the kinetic lattice gas model is a powerful theoretical tool by which, in addition to numerical results, explicit formulas can be obtained to elucidate the underlying physics. This allows one to extract simplified pictures of and approximations to complicated processes, as shown above with precursor-mediated adsorption as an example. This task of theory is increasingly overlooked with the trend to using cheaper computer power for numerical simulations. Unfortunately, many of the simulations of adsorbate kinetics are based on unnecessarily oversimplified assumptions (for example, constant sticking coefficients, constant prefactors etc.) which rarely are spelled out because the physics has been introduced in terms of a set of computational instructions rather than formulating the theory rigorously, e.g., based on a master equation. [Pg.477]

Most traditional models focus on looking for equilibrium solutions among some set of (pre-defined) aggregate variables. The LEs are effectively mean-field equations, in which certain variables (i.e. attrition rate) are assumed to represent an entire force, the equilibrium state is explicitly solved for and declared the battle outcome. In contrast, ABMs focus on understanding the kinds of emergent patterns that might arise while the overall system is out of (or far from) equilibrium. [Pg.601]

This equation is known as the Br0nsted-Bjerrum equation. Because y% appears in the denominator, it explicitly acknowledges the premise of TST that there is an equilibrium between the reactants and the transition state. Equation (9-27) provides the basis for understanding the direction and magnitude of rate effects arising from changes of reaction medium. This approach will be used to formulate effects of solvent and inert electrolytes in the sections that follow. [Pg.204]


See other pages where Equilibria explicit equations is mentioned: [Pg.1504]    [Pg.232]    [Pg.103]    [Pg.12]    [Pg.228]    [Pg.625]    [Pg.1326]    [Pg.1807]    [Pg.645]    [Pg.1799]    [Pg.242]    [Pg.1508]    [Pg.454]    [Pg.80]    [Pg.150]    [Pg.241]    [Pg.407]    [Pg.820]    [Pg.326]    [Pg.187]    [Pg.171]    [Pg.63]    [Pg.220]    [Pg.664]    [Pg.686]    [Pg.503]    [Pg.457]    [Pg.364]    [Pg.282]    [Pg.51]    [Pg.280]    [Pg.440]    [Pg.469]    [Pg.275]    [Pg.43]   
See also in sourсe #XX -- [ Pg.41 , Pg.64 ]




SEARCH



Explicit equations

Explicitness

© 2024 chempedia.info