Silver free energy change

The reactivities of potassium and silver with water represent extremes in the spontaneity of electron-transfer reactions. The redox reaction between two other metals illustrates less drastic differences in reactivity. Figure 19-5 shows the reaction that occurs between zinc metal and an aqueous solution of copper(II) sulfate zinc slowly dissolves, and copper metal precipitates. This spontaneous reaction has a negative standard free energy change, as does the reaction of potassium with water ... 

The silver oxide-zinc battery used in hearing aids delivers a voltage of 1.60 V. Calculate the free-energy change (in kilojoules) for the cell reaction... 

Flory s mathematical relationships for the free energy change that occurs when a solute is mixed with a solvent for the solution phase and the solid phase have been discussed as they apply to collagen assembly by Silver (1987). The free energy of mixing of solute and solvent per mole of molecules is equivalent to the change in chemical potential of a desired state (p)... 

In fact, each electron transfer half-reaction involves a free energy change following this formula. To reach the total variation in AG we sum the contributions of the two half-reactions, remembering that one is a reduction and the other an oxidation. For example, for the dissolution of silver chloride under standard conditions... 

Another procedure for testing the third law of thermodynamics is to combine heat content with entropy data for a given reaction, and so to determine the free energy change, the value of which is known from direct measurement. The standard free energy change for the formation of silver oxide, i.e., for the reaction 2Ag(s) + = Ag20(s), can be derived from... 

The free energy change for the dissociation of solid silver chloride to yield chlorine gas at the pressure pch is zero, since the system is in equilibrium hence, the free energy change of the second reaction is identical with that for the over-all process. An electrode consisting of chlorine gas at the dissociation pressure peu would thus have the same potential, in a given chloride ion solution, as would the Ag, AgCl(s) electrode. 

The solubility of silver iodate in water is 1.771 X 10" mole liter at 25 C. Calculate the standard free energy change of the process AgIOs( ) Ag" + lOr Using the standard potential of the Ag, Ag+ electrode, calculate that of the Ag, AgIOs( ), lOi electrode at 25° C. 

Although the vacuum level is of no practical reference, the question arises of whether the standard potential or energy of the hydrogen reference electrode (NHE) can be quantitatively related to the vacuum level. The first quantitative approach, which was a straightforward one, was published by Lohmann [9]. He examined free energy changes associated with the reduction of silver ... 

Considering the free energy changes associated with the reduction of silver, one can derive the relationship between vacuum and the NHE. The energy involved with various reactions can be presented by considering the following four steps [8] ... 

The olefin solubility in a silver-PEO complex has been also reported. AgBp4-PEO absorbed 45 cm (STP) of propylene per 1 g of silver-PEO complex, at 30 °C and 93 kPa [17]. The relationship between the olefin solubility and the structure can be understood by an ab initio calculation based on the density functional theory of the model system. The theoretical calculation shows that the bond length between the silver ion and the closest anion atom in the AgBp4-PEO film changes from 2.309 to 2.506 A with the addition of ethylene, and the free energy for the formation of an ethylene adduct with AgBF4 is favorable for an ethylene-silver complex in PEO [15, 18-19] (Fig. 9-5). 

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