Relative partial molar free energy

These expressions comprise the nonideal terms in the previous equations for the chemical potential, Eqs. (30) and (31 ). They may therefore be regarded as the excess relative partial molar free energy, or chemical potential, frequently used in the treatment of solutions of nonelectrolytesi.e, the chemical potential in excess (algebraically) of the ideal contribution, which is —RTV2/M in dilute solutions. 

One must recognize that the partial molar free energy is not a measurable quantity because the absolute value of the free energy is not measurable. However, the relative partial molar free energy, AGa, defined as follows, is measurable... 

Besides the partial molar and the relative partial molar free energies of the components, some other important thermodynamic properties are the partial molar and the relative partial molar enthalpies and entropies. The partial molar enthalpy and entropy of the component A are defined by... 

The relative partial molar free energy of A is written in terms of the integral molar free energy of the solution as... 

The relationships presented thus far for partial, integral and relative partial molar free energies are applicable in a similar manner to entropy, enthalpy and also volume. 

Figure 5.4 Relative partial molar free energy of oxygen. AGq, of Fei, 0 as a function of composition (log x). (Taken from the data given in S0rensen, 1981.)...

On the basis of dissociative solution, i.e., hydrogen is absorbed as H atoms rather than H2 molecules, the relative partial molar free energy of absorption is related to the equilibrium constant via the equilibrium hydrogen pressure (Equation 3). Values of the relative partial molar enthalpy as a function of hy-... 

Gj -G° is the change in molar free energy of / due to the change in state from the standard state to the state of solution of a particular composition. This is called the partial molar free energy of mixing or relative partial molar free energy of i and is designated... 

Consider the relative partial molar free energy, G,w,... 

At a given temperature T, this reaction has a hydrogen equilibrium pressure H. Consider now a solid solution of this metal with a non-hydride forming metal (B). The relative partial molar free energy of A in the alloy is AGa- If the resulting alloy AB reacts with hydrogen as... 

Quantities that are determinable from experiments can be derived from Equation 12.28. For example, by differentiating the expression with respect to Ni, the number of solvent molecules, and multiplying the result by Avogadro s number, the relative partial molar free energy AG, is obtained ... 

We note for emphasis (also from Equation 12.43) that at the temperature T = 0 the excess, relative, partial molar-free energy, AG, due to polymer-solvent interactions is zero and deviations from ideahty vanish. 

The polymer concentration (02m) at which p = p, or the aetivity of the solvent is unity, represents the composition at swelling equilibrium. This is the coneentration at which the relative chemical potential (qi - p ), or the relative partial molar free energy AGi, plotted against 02, reaches a maximum. To locate this composition we equate (pi - p ) of Eq. (3.131) to zero, obtaining thereby... 

G. - gV) is called the partial molar free energy of mixing, or relative partial molar free energy of component i, and is denoted by G.. Thus, Eq.(7.3) takes the shape... 

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