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In electrochemistry, the Nernst equation is a chemical thermodynamical relationship that permits the calculation of the reduction potential of a reaction (half-cell or full cell reaction) from the standard electrode potential, absolute temperature, the number of electrons involved in the redox reaction, and activities (often approximated by concentrations) of the chemical species undergoing ...
Source: [1] The potential splits the space in two parts (x < 0 and x > 0).In each of these parts the potential is zero, and the Schrödinger equation reduces to =; this is a linear differential equation with constant coefficients, whose solutions are linear combinations of e ikx and e −ikx, where the wave number k is related to the energy by =.
In aqueous solutions, redox potential is a measure of the tendency of the solution to either gain or lose electrons in a reaction. A solution with a higher (more positive) reduction potential than some other molecule will have a tendency to gain electrons from this molecule (i.e. to be reduced by oxidizing this other molecule) and a solution with a lower (more negative) reduction potential ...
The second factor to be considered are the values of the concentrations taken into account in the Nernst equation. To define a formal reduction potential for a biochemical reaction, the pH value, the concentrations values and the hypotheses made on the activity coefficients must always be clearly indicated.
The cell reaction is generally endothermic: i.e. it will extract heat from its environment. [ citation needed ] The Gibbs energy calculation generally assumes an infinite thermal reservoir to maintain a constant temperature, but in a practical case, the reaction will cool the electrode interface and slow the reaction occurring there.
The larger the value of the standard reduction potential, the easier it is for the element to be reduced (gain electrons); in other words, they are better oxidizing agents. For example, F 2 has a standard reduction potential of +2.87 V and Li + has −3.05 V: F 2 (g) + 2 e − ⇌ 2 F − = +2.87 V Li + + e − ⇌ Li (s) = −3.05 V
This ongoing current in both directions is called the exchange current density. When the potential is set more negative than the formal potential, the cathodic current is greater than the anodic current. Written as a reduction, cathodic current is positive. The net current density is the difference between the cathodic and anodic current density.
A thermodynamic potential (or more accurately, a thermodynamic potential energy) [1] [2] is a scalar quantity used to represent the thermodynamic state of a system. Just as in mechanics, where potential energy is defined as capacity to do work, similarly different potentials have different meanings.