Equilibrium constant ratios

Study the influence of the equilibrium constant ratio KB/KA, for the two components A and B, on the resolution of the peaks, as given by the time difference between the peaks. 

Schiff s base formation occurs by condensation of the free amine base with aldehyde A in EtOAc/MeOff. The free amine base solution of glycine methyl ester in methanol is generated from the corresponding hydrochloride and triethylamine. Table 4 shows the reaction concentration profiles at 20-25°C. The Schiffs base formation is second order with respect to both the aldehyde and glycine ester. The equilibrium constant (ratio k(forward)/ k(reverse)) is calculated to be 67. 

An adsorption equilibrium constant (ratio of adsorption and desorption rate coefficients) must decrease with increasing temperature, provided adsorption is exothermic, as is almost always the case. 

Equilibrium compositions of re-etherification products were determined in terms of reagent ratios. Re-etherification rate constant and equilibrium constant ratios were obtained (Table 1). 

This is a very large number— ten billion times larger than the number in a mole The only way an equilibrium constant ratio can become so huge is for the concentration of one or more reacting species to be very close to zero. If the denominator of a ratio is... 

Low pressure rate coefficients and equilibrium constant ratios for HNO, T = 300 K. 

We list in Table 11 the molecular parameters needed to estimate kg for dissociation from each of the three electronic states, and to estimate the equilibrium constant ratios. In Table 12, we summarize the predicted kg s and ratios for a T= 300 K. The recombination ratios for the two excited states relative to the ground state are given by... 

When oil and gas are produced simultaneously into a separator a certain amount (mass fraction) of each component (e.g. butane) will be in the vapour phase and the rest in the liquid phase. This can be described using phase diagrams (such as those described in section 4.2) which describe the behaviour of multi-component mixtures at various temperatures and pressures. However to determine how much of each component goes into the gas or liquid phase the equilibrium constants (or equilibrium vapour liquid ratios) K must be known. 

The solubilization of diverse solutes in micelles is most often examined in tenns of partitioning equilibria, where an equilibrium constant K defines the ratio of the mole fraction of solute in the micelle (X and the mole fraction of solute in the aqueous pseudophase. This ratio serves to define the free energy of solubilization -RT In K). 

This distinction between Kd and D is important. The partition coefficient is an equilibrium constant and has a fixed value for the solute s partitioning between the two phases. The value of the distribution ratio, however, changes with solution conditions if the relative amounts of forms A and B change. If we know the equilibrium reactions taking place within each phase and between the phases, we can derive an algebraic relationship between Kd and D. 

It is possible to measure equilibrium constants and heats of reaction in the gas phase by using mass spectrometers of special configuration. With proton-transfer reactions, for example, the equilibrium constant can be determined by measuring the ratio of two reactant species competing for protons. Table 4.13 compares of phenol ionizations. 

The simplest mode of IGC is the infinite dilution mode , effected when the adsorbing species is present at very low concentration in a non-adsorbing carrier gas. Under such conditions, the adsorption may be assumed to be sub-monolayer, and if one assumes in addition that the surface is energetically homogeneous with respect to the adsorption (often an acceptable assumption for dispersion-force-only adsorbates), the isotherm will be linear (Henry s Law), i.e. the amount adsorbed will be linearly dependent on the partial saturation of the gas. The proportionality factor is the adsorption equilibrium constant, which is the ratio of the volume of gas adsorbed per unit area of solid to its relative saturation in the carrier. The quantity measured experimentally is the relative retention volume, Vn, for a gas sample injected into the column. It is the volume of carrier gas required to completely elute the sample, relative to the amount required to elute a non-adsorbing probe, i.e. 

The vapor-solid equilibrium constant is determined experimentally and is defined as the ratio of the mol fraction of the hydrocarbon component in gas on a water-free basis to the mol fraction of the hydrocarbon component in the solid on a water-free basis. That is ... 

At equilibrium, the ratio of concentrations is an equilibrium constant, so we can write the standard free energy change for the process as... 

Many equilibrium calculations are accomplished using tlie plrase equilibrium constant K,. Tliis constant has been referred to in industry as a coiiiponential split factor, since it provides the ratio of the mole fractions of a component in two equilibrium pluises. The defining equation is... 

Molecular orbital calculations have been used to estimate equilibrium constants, although up to the present these attempts have not met with much success. Using calculations of this type, 2- and 4-hydroxypyridine 1-oxide were predicted to be more stable than 1-hydroxypyrid-2- and -4-one by ca. 20 kcal/mole, which corresponds to a ratio of ca. 10 between the forms. It was later shown experimentally that, at least in the series of 4-substituted compounds, there is very little energy difference between the forms and that the ratio between them is about unity. Molecular orbital calculations for... 

If these measurements are made at a pH where only the neutral molecules are present, the ratio is equal to the constant K. This restriction about pH is necessary because and are ordinarily composite, their relationship to the equilibrium constants and pA values being given by the relevant equations, ... 

It follows from equation 1.14 that for any constant ratio of a /a the E vs. pH relationship will be linear with a slope -0-059m/z, and that when = 1 fhe intercept of the curve on the E axis (i.e. pH= 0) will be E, the standard equilibrium potential, which by definition is the potential when the species involved in the equilibrium are at unit activity. 

This means that, with increasing length of chain, the equilibrium constants K1 and K2 (the first and second dissociation constants at infinite dilution of the acid) should not tend to equality rather their ratio K1/K2 should tend toward the value 4, as recognized by Adams.1... 

You may wonder why the equilibrium constant, 11, has no units. The reason is that each term in the reaction quotient represents the ratio of the measured pressure of the gas to the thermodynamic standard state of one atmosphere. Thus the quotient (f3No2)2/f>N2o4 in Experiment 1 becomes... 

The equilibrium constant for this system, like all equilibrium constants, changes with temperature. At 100°C, K far the N204-N02 system is 11 at 150°C, it has a different value, about 110. Any mixture of N02 and N204 at 100°C will react in such a way that the ratio (Eno /EnjO, becomes equal to 11. At 150°C, reaction occurs until this ratio becomes 110. 

The equilibrium constant is defined by K, K = y/x, and the portion coefficient is also defined by K as a ratio of CAu/CA1 which is constant. Based on the value of K, single or multi-stage extractions are performed to do a perfect job in bioseparation. 

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