Formation molar Gibbs energy

Besides equilibriumconstants, additional thermodynamic data were included, if available, although little emphasis was put on their completeness. The data for primary master species comprise the standard molar thermodynamic properties of formation from the elements (AfG standard molar Gibbs energy of formation AfH°m standard molar enthalpy of formation ApSm- standard molar entropy of formation), the standard molar entropy (5m), the standard molar isobaric heat capacity (Cp.m), the coefficients Afa, Afb, and Afc for the temperature-dependent molar isobaric heat capacity equation... 

The conventional thermodynamic standard state values of the Gibbs energy of formation and standard enthalpy of formation of elements in their standard states are A(G — 0 and ArH = 0. Conventional values of the standard molar Gibbs energy of formation and standard molar enthalpy of formation of the hydrated proton are ArC (H +, aq) = 0 and Ar// (H +, aq) = 0. In addition, the standard molar entropy of the hydrated proton is taken as zero 5 (H+, aq) = 0. This convention produces negative standard entropies for some ions. 

Table 2.2 Standard molar Gibbs energies of formation and standard molar enthalpies of formation for some anions at 25 "C (in kJ mol - )...

Note that gw0 is the molar Gibbs energy of formation of the standard hydrate at the reference conditions (To and Pq), ht is the molar enthalpy, and vt is the molar... 

The molar Gibbs energy of micelle formation is the Gibbs energy difference between a mole of monomers in micelles and the standard chemical potential in dilute solution ... 

As an example, we consider hydrochloric acid in aqueous solution, for which the standard molar Gibbs energy of formation is known. According to Equation (11.30),... 

The extent of the reaction of carbon dioxide with water to form carbonic acid is fairly well known—less than 1%. However, for thermodynamic purposes we make no distinction between the two nonionized species, C02 and H2C03. We are thus concerned with the sum of the concentration of these species, a quantity that can be determined experimentally. We must therefore develop the methods used to define the standard state of the combined nonionized species and the standard molar Gibbs energies of formation. 

When the standard Gibbs energy of formation of the hydrogen ion is defined as zero, the standard molar Gibbs energy of hydronium ion must equal that of water. The change of state related to AGP(H30 + ) is... 

These are the properties of the monatomic gas at a pressure of 1 bar. It should be pointed out that this standard molar Gibbs energy is not the AfG° of thermodynamic tables because there the convention in thermodynamics is that the standard formation properties of elements in their reference states are set equal to zero at each temperature. However, the standard molar entropies of monatomic gases without electronic excitation calculated using equation 2.8-11 are given in thermodynamic tables. 

This reaction stops when the liquid composition reaches point J, where SiC becomes stable in contact with the liquid and precipitated C. At this point, the equilibrium molar fraction of Si dissolved in M, X (Figure 7.2), is related to the partial enthalpy of mixing of Si in M, AHsi(M) (neglecting the partial excess entropy of mixing), and to the molar Gibbs energy of formation of SiC, AGf(SiC), by the equation ... 

The chemical potential of a substance corresponds at 298 K and 100 kPa (1 bar) to its molar Gibbs energy of formation if the zero points of the potential scales are appropriately chosen. Therefore, when looking for the chemical potential, tables in which this quantity is listed can be used. 

The standard molar Gibbs energy of formation of URh3 can be calculated from ... 

With this equation the standard molar Gibbs energy of formation of URh3 can be calculated for each temperature, and is given in Table 9.4. With the linear regression function on a pocket calculator the following equation is derived for A/ 0 (URh3) as function of temperature ... 

The equihbrium association constant K is directly related to the change of the molar Gibbs energy attributed to complex formation AG° ... 

EFI/PRO] Efimov, M. E., Prokopenko, L V., Tsirelnikov, V. L, Troyanov, S. L, Medvedev, V. A., Berezovskii, G. A., Paukov, L E., Thermodynamic properties of zirconium chlorides. I. The standard molar enthalpy of formation, the low-temperature heat capacity, the standard molar entropy, and the standard molar Gibbs energy of formation of zirconium trichloride, J. Chem. Thermodyn., 19, (1987), 353-358. Cited on pages 163, 164, 333,335,338. 

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