Electromotive force standard

This gives a standard electromotive force (EMF) at equilibrium... 

Table 6.11 lists, to the right of the arrows, reducing agents or disposition to electron loss or disposition to oxidation in order of increasing strength. Such a list is more popularly called the electromotive force, or emf, series. The maximum potential difference which can be measured for a given cell is called the electromotive force (abbreviated emf) and represented by the symbol Ecell. It may be recounted that the emf values reported in Table 6.11 are for those cells under specified standard conditions in which all the concentrations are 1 M and pressures are 1 atm. The emf of such a cell is said to be its standard electromotive force, and is given by the symbol E ell. 

E° Equilibrium Standard electromotive force H Henry (unit of self-inductance and mutual inductance)... 

The standard electromotive force (emf), °q, at equilibrium (no current flowing) under standard conditions is then calculated as follows ... 

Thus, if we start with our reactants and products under standard conditions and allow the reaction to proceed to equilibrium, an amount of energy AG° becomes available for external work. In the context of doing external electrical work, an oxidation—reduction reaction can generate a standard electromotive force AE° given by... 

In the given example (ozn++ = 1> cn++ — D the cell is operating under standard conditions, the calculated electromotive force E, therefore, represents the standard electromotive force Ea. 

Young s modulus standard electrode potential standard electromotive force half-wave potential first-order elimination second-order elimination for example... 

The primary medium effect of an electrolyte can also be calculated from the standard potentials of a galvanic cell. The difference of the standard electromotive forces E and E " of the galvanic cells... 

The valne (E°) for the standard electromotive force of a cell in which hydrogen nnder standard conditions is oxidized to hydroninm ions (solvated protons) at the left-hand electrode. This value is used as a standard to measure electrode potentials. 

This cell will have a standard electromotive force say and, since AG° —FEy2.y follows that E < = - 2 — electromotive force of any... 

According to its definition, the standard (reduction) potential of the A/A couple is the standard electromotive force of a cell in which an A/A electrode (where the activities of A and A are made unity) is opposed to an NHE (normal hydrogen electrode) whose potential is assigned to zero by convention. 

The equilibrium constant for a redox reaction can be found from the standard electromotive force of a cell. 

In equation 7-3 the term (RT/a ln K can be replaced by E , which is known as the standard electromotive force of the cell. E° is seen to be the value of the cell electromotive force that would be obtained if all of the substances in the reaction were at unit activity. On the other hand, if the system were at equilibrium, then the value of E as well as AG would be zero. 

Ethanol is considered as the ideal fuel for the so-called direct alcohol fuel cells (DAFCs). This is because ethanol has a number of advantages over methanol it can be produced in a sustainable manner, easily stored and transported, and is less toxic or corrosive than methanol. The theoretical mass energy of ethanol is 8.0 kWh kg compared to 6.1 kWh kg" for methanol. The complete oxidation of ethanol releases 12 electrons per molecule its standard electromotive force E° q =1145V, is similar to that of methanol. 

Here, Eo refers to the standard electromotive force, n is the number of electrons involved in the reaction, F is the Faraday constant, R is the gas constant, T is the absolute temperature and a is the activity of materials. 

Standard electromotive force is the difference between the standard electrode potential (d> ) of the positive and negative electrodes. 

The decrease in free energy of the system in a spontaneous redox reaction is equal to the electrical work done by the system on the surroundings, or AG = nFE. The equilibrium constant for a redox reaction can be found from the standard electromotive force of a cell. 10. The Nernst equation gives the relationship between the cell emf and the concentrations of the reactants and products under non-standard-state conditions. Batteries, which consist of one or more galvanic cells, are used widely as self-contained power sources. Some of the better-known batteries are the dry cell, such as the Leclanche cell, the mercury battery, and the lead storage battery used in automobiles. Fuel cells produce electrical energy from a continuous supply of reactants. 

TABLE 4.2 Eixcerpted listing of standard electromotive force potentials"... 

Standard Electromotive Force Potentials Galvanic Series of Metals Galvanic Series of Metals in Sea Water Corrosion... 

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