Gibbs standard

The equilibrium eonstant K is related to the Gibbs standard free energy ehange AG by... 

If two reactions differ in maximum work by a certain amount 8wm (= -SAG ), it follows from the Brpnsted relation [when taking into account the Arrhenius equation and the known relation between the equilibrium constant and the Gibbs standard free energy of reaction, A m = exp(-AGm/J r)] that their activation energies will differ by a fraction of this work, with the opposite sign ... 

It is worthwhile to compare the stability differences of the analogous hydrindanes and decalins. In both cases, the Gibbs standard free energy differences favor the trans isomers, by 1.3 kJ mol" in the hydrindanes and by about 10 kJ mol in the decalins (94MI3). This direction of the difference is in contrast with that found for the 1,3-heteroanalogs of cis- and trans-hydrindane. 

The Gibbs equation relates the change in a reaction s Gibbs standard free energy (AG°) to its equilibrium constant ... 

Chemical composition and Gibbs standard free energy of formation of Fe(II)-Fe(III) hy-droxysulphate green rust and Fe(II) hydroxide. Clay Miner. 34 499-510... 

As the Gibbs standard free energy for the peptide-nonpolar ligand interaction decreases, and AGassoci becomes increasingly negative, enhanced retention will occur. The relationship between the relative retention of a specific peptide in a RPC separation process carried out at constant pressure, P, and constant molar volume, V, can thus be expressed in terms of the following well-known, fundamental thermodynamic relationship ... 

The problem is that the energy change that correlates with Keq is not AH0 but AG° (the so-called Gibbs standard free energy )5, and if we know AG°, we can calculate Km by the equation... 

The racemisations terminated in equilibria in which one component was in excess over the other with equihbrium constants different for the two chiral media. From the temperature dependence of the equilibrium constants they found the differences of heat contents [AH =. Q and 1.8 kj mol i) and Gibbs standard free energies (dG°=0.30 and 0.34 kJ mol-i) respectively for bromocamphorsulphonate and cinchomium ions as the added chiral species. 

The Gibbs standard free-energy change (AG° and an entropy (AS°) component ... 

Gibbs standard free energy change (AGe) The mathematical function of temperature that governs a reaction equilibrium. 

Wolf and Tumambac (03JPC(A)815) reported the study of a compound related to 38, the l,8-bis(2,2 -diphenyl-4,4 -dipyridyl)naphthalene (65). Rate constants obtained between -65.0 and 40.3 °C allowed the determination of the Gibbs standard activation energy AG for the diastereoisome-rization of 65 as 70.4 kj mol . The rotational activation enthalpy AH and the rotational activation entropy AS were calculated from the Eyring plot as 57.5 kJ moG and -43.4 J moG, respectively. 

Owing to the exponential dependence of the equilibrium constant on the Gibbs standard enthalpy of reaction, errors in are multiplied exponentially. 

The gas-phase acidity of a compound AH is defined as the variation of the Gibbs standard free energy (AG°) of the reaction... 

Thermodynamic cycles [90-93] can be used to relate the different energy patterns, such as the Gibbs standard chemical reaction energy (AoG°), the Gibbs standard electrochemical energy (—FE°) for the transfer of one electron, and bond dissociation energy (Scheme 23). 

When the left part is subtracted from the right part of the reaction, the standard potential and the change in the Gibbs standard energy for this electrochemical pah-are given in short order as... 

It is important to realize that from the adsorption equilibrium data (i.e., the experimental isotherm), generally it cannot be distinguished between the effects of surface heterogeneity and lateral interactions. Consider the adsorption equilibrium constant K it can be related to the Gibbs standard free energy of adsorption ... 

As far as the thermodynamics of the interaction of a protein or peptide species i with the nonpolar stationary phase of an RPC or HIC sorbent is concerned, retention is associated with a decrease in the Gibbs standard free energy (AG soc,). Because the equilibrium distribution coefficient, ATassoc,i> related to the overall energy change in Gibbs free energy, i.e.. 

The relationship (Equation 4.3) that correlates energy change with equilibrium constant involves standard enthalpy (AH°), temperature (K), and standard entropy (AS°) and is called the Gibbs standard free energy (AG°) ... 

The Gibbs standard liree-energy change (G°) has an enthalpy (H°) component and an entropy (A5°) component (T is the temperature in kelvins) ... 

If a reaction has gone to completion, a certain amount of energy has been released. The eqnilibrium constant can be related directly to the thermodynamic function called the Gibbs standard free enei change, AG°. At equilibrium. 

The Gibbs standard free energy change is related to two other thermodynamic quantities the change in enthalpy, AH°, and the change in entropy, A5 . 

If we want to distinguish the irreversible steps from the quasi-stationary ones, we have to look to another chemical quantity, the chemical potential (yw). Up to now, all the energy values in the energy span model were Gibbs standard energies, which is the information we can obtain from a typical quantum mechanical calculation of a catalytic cycle. However, the real nonstandard Gibbs energy of each intermediate (i.e., the chemical potential) must include their concentrations [46] ... 

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