Faraday‘s constant

These three terms represent contributions to the flux from migration, diffusion, and convection, respectively. The bulk fluid velocity is determined from the equations of motion. Equation 25, with the convection term neglected, is frequently referred to as the Nemst-Planck equation. In systems containing charged species, ions experience a force from the electric field. This effect is called migration. The charge number of the ion is Eis Faraday s constant, is the ionic mobiUty, and O is the electric potential. The ionic mobiUty and the diffusion coefficient are related ... 

Faraday s constant, F, is the magnitude of the charge per mole of electrons (the product of the elementary charge e and Avogadro s constant NA) ... 

To determine the amount of electrons supplied by a given charge, we use Faraday s constant, F, the magnitude of the charge per mole of electrons (Section 12.4). Because the charge supplied is wF, where n is the amount of electrons (in moles), and Q = nF, it follows that... 

Step 3 Substitute , the current, and Faraday s constant into Eq. 8 rearranged to t = Fn/I and solve for time. 

In the case of electrocatalytic operation, a galvanostat was used to apply constant currents I between the catalyst and a counter electrode deposited at the outer walls of the YSZ tube. In this way, oxygen is supplied to the Ag-based catalyst at a rate I/2F mol 0/s, where F is Faraday s constant. In this case the catalyst acts as an electrocatalyst [9,12,14]. 

Provided the reaction is, in some sense, reversible, so that equilibrium can be attained, and provided the reactants and products arc all gas-phase, solution or solid-state species with well-defined free energies, it is possible to define the free energies for all such reactions under any defined reaction conditions with respect to a standard process this is conventionally chosen to be the hydrogen evolution/oxidation process shown in (1.11). The relationship between the relative free energy of a process and the emf of a hypothetical cell with the reaction (1.11) as the cathode process is given by the expression AC = — nFE, or, for the free energy and potential under standard conditions, AG° = — nFEl where n is the number of electrons involved in the process, F is Faraday s constant and E is the emf. 

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