Gibbs energy difference maximum value

The Gibbs energy difference between the native and denatured states is represented by Eq. (8), a function with an extremum (Fig. 6). Its maximum value is reached at the temperature Tm, which can be determined from the condition... 

An electrical potential difference between the electrodes of an electrochemical cell (called the cell potential) causes a flow of electrons in the circuit that connects those electrodes and therefore produces electrical work. If the cell operates under reversible conditions and at constant composition, the work produced reaches a maximum value and, at constant temperature and pressure, can be identified with the Gibbs energy change of the net chemical process that occurs at the electrodes [180,316]. This is only achieved when the cell potential is balanced by the potential of an external source, so that the net current is zero. The value of this potential is known as the zero-current cell potential or the electromotive force (emf) of the cell, and it is represented by E. The relationship between E and the reaction Gibbs energy is given by... 

The maximum of the Gibbs free enthalpy between the ground states of substrate and product forms the Gibbs free enthalpy of activation with the energy difference AG7, which determines the rate constant of the reaction, like every catalyst, an enzyme decreases the value of AG and thus accelerates the reaction. (An agent increasing the value of AG7 is termed an anti-catalyst .)... 

FIGURE 10.5 Diagram of the Gibbs free energy versus nucleus radius at three different contact angles (0 = 90°, 110°, 180°). The curves attain their maximum value in correspondence of the critical radius R. Input data dc = 1.5 = 1.9 x 10" m = 0.004 J/m. ... 

To solve this equation, it is convenient to define a critical region of values of n in which the Gibbs energies of clusters differ from the maximum AG less than kT, the energy of thermal fluctuations (cf. Fig. 3), extending a cluster size range of InkT, where y = (d AG Jdn. . 

In 2001, Kakiuchi et al. showed how the relationship between the Gibbs energy of adsorption and transfer for an ionic surfactant leads to the adsorption maximum being attained when the value of the applied potential difference is close to that of the standard ion-transfer potential. This takes place also in the presence of concentration gradients in the vicinity of the interface and predicts that the adsorption is maximum around the half-wave potential in voltammetric measurements [78]. This relationship is also applied in electrocapillary emulsification. 

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