Equilibrium factor definition

Also, the terra equilibrium constant often is used to describe K-factor. This term is misleading since K-factors definitely are not constant. K-factors change with pressure, temperature, and type of mixture. Thus we have elected to use the terms equilibrium ratio or K-value. 

In Chapter 8 the equilibrium factor for a single adsorbed species was defined by analogy with the relative volatility. This definition is easily extended to a binary or multicomponent system. For competitive sorption the binary separation factor is defined by... 

Where activated carbon is a potential treatment technology, the first evaluation step is generally to run simple isotherms to determine feasibility. Isotherms are based on batch treatment where impurities reach equilibrium on available carbon surface. While such tests provide an indication of the maximum amount of impurity a GAC can adsorb, it cannot give definite scale up data for a GAC operation due to several factors ... 

One chemical will be a solvent for another if the molecules are able to co-exist on a molecular scale, i.e. the molecules show no tendency to separate. In these circumstances we say that the two species are compatible. The definition concerns equilibrium properties and gives no indication of the rate of solution which will depend on other factors such as temperature, the molecular size of the solvent and the size of voids in the solute. 

This last inflammability parameter presents problems. After stating its definition it will be seen that measuring autoignition temperature proves to be a difficult exercise because its measurement is sensitive to the experimental conditions, even more sensitive than for flashpoints. Worse, this parameter seems to be controlled by kinetic factors far more complex to master than the thermodynamic factors that probably control flashpoints (in fact it is a liquid/vapour equilibrium). So whilst the influence of the nature of the cup metal on a flashpoint has never been demonstrated, this demonstration was easily made with autoignition temperatures. 

The coordinate pertaining to solvent reorganization, z, is the same fictitious charge number as already considered in the Hush-Marcus model of outer-sphere electron transfer (Section 1.4.2), and so is the definition of 2q [equation (1.27)] and the difference between the Hush and Marcus estimation of this parameter. The coordinated describing the cleavage of the bond is the bond length, y, referred to its equilibrium value in the reactant, yRX. Db is the bond dissociation energy and the shape factor ft is defined as... 

This introduces a new unknown (and free at this stage) coefficient K. In the case of a system of molecules in a thermal bath (definitely not the one we consider), there is a relation between D and K such that, at thermal equilibrium, the equilibrium density in the potential (h is given by Boltzmann s law. This requires that K = mD/hgT, where kg is Boltzmann s constant and T the absolute temperature. In Eq. (12) the factor p in front of in is to ensure that, if... 

The rate-controlling step is the elementary reaction that has the largest control factor (CF) of all the steps. The control factor for any rate constant in a sequence of reactions is the partial derivative of In V (where v is the overall velocity) with respect to In k in which all other rate constants (kj) and equilibrium constants (Kj) are held constant. Thus, CF = (5 In v/d In ki)K kg. This definition is useful in interpreting kinetic isotope effects. See Rate-Determining Step Kinetic Isotope Effects... 

Note that reactions 2.14, 2.15, and 2.23 involve fractional stoichiometric coefficients on the left-hand sides. This is because we wanted to define conventional enthalpies of formation (etc.) of one mole of each of the respective products. However, if we are not concerned about the conventional thermodynamic quantities of formation, we can get rid of fractional coefficients by multiplying throughout by the appropriate factor. For example, reaction 2.14 could be doubled, whereupon AG° becomes 2AG, AH° = 2AH , and AS° = 2ASf, and the right-hand sides of Eqs. 2.21 and 2.22 must be squared so that the new equilibrium constant K = K2 = 1.23 x 1083 bar-3. Thus, whenever we give a numerical value for an equilibrium constant or an associated thermodynamic quantity, we must make clear how we chose to define the equilibrium. The concentrations we calculate from an equilibrium constant will, of course, be the same, no matter how it was defined. Sometimes, as in Eq. 2.22, the units given for K will imply the definition, but in certain cases such as reaction 2.23 K is dimensionless. 

Semiconductors (cont.) equilibrium in. 1076 exponential law, 1081 germanium as, properties, 1076 hole movement 1076 impedance of, 1136 importance of, 785 limiting current 1088 n-, in thermal reactions, 1086 n-pjunction, 1073, 1081 p- in thermal reactions. 1086 photoactivity of, 1089 photoelec trochemistiy, 1073 photos timulated electrodeposition on. 1345 potential variation with distance in, 1082 silicon as, properties, 1076 surface states. 1086 symmetry factor in, 1082 thermal reactions, definition, 1088 Sen, 1495... 

It is easy to see some of the factors affecting the equilibrium composition. From the definition in Eq. 9.42, large values of Kp dictate that the products of the reaction are favored over the reactants that is, thermodynamics pushes the forward reaction toward completion. From Eq. 9.44, a reaction that is very exothermic, AH° << 0, favors product formation that is, Kp will be very large. 

The equations for gas-liquid equilibria calculations and the definition of equilibrium ratio (K-factor) were discussed in Chapter 12. This chapter will examine K-factor coirelations. 

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