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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 ...
The Nernst–Planck equation is a conservation of mass equation used to describe the motion of a charged chemical species in a fluid medium. It extends Fick's law of diffusion for the case where the diffusing particles are also moved with respect to the fluid by electrostatic forces. [1][2] It is named after Walther Nernst and Max Planck.
Distribution law or the Nernst's distribution law[1][2][better source needed] gives a generalisation which governs the distribution of a solute between two immiscible solvents. This law was first given by Nernst who studied the distribution of several solutes between different appropriate pairs of solvents. C 1 /C 2 = K d.
Solving the Nernst equation for the half-reaction of reduction of two protons into hydrogen gas gives: 2 H+ + 2 e− ⇌ H2. In biochemistry and in biological fluids, at pH = 7, it is thus important to note that the reduction potential of the protons ( H +) into hydrogen gas H. 2 is no longer zero as with the standard hydrogen electrode (SHE ...
For realistic situations, the time constant usually lies in the 1—100 millisecond range. In most cases, changes in the conductance of ion channels occur on a faster time scale, so an RC circuit is not a good approximation; however, the differential equation used to model a membrane patch is commonly a modified version of the RC circuit equation.
The third law of thermodynamics states that the entropy of a system at absolute zero is a well-defined constant. This is because a system at zero temperature exists in its ground state, so that its entropy is determined only by the degeneracy of the ground state. In 1912 Nernst stated the law thus: "It is impossible for any procedure to lead to ...
Concentration cell. In battery technology, a concentration cell is a limited form of a galvanic cell that has two equivalent half-cells of the same composition differing only in concentrations. One can calculate the potential developed by such a cell using the Nernst equation. [1] A concentration cell produces a small voltage as it attempts to ...
Heterogeneous water oxidation. Water oxidation is one of the half reactions of water splitting: 2H 2 O → O 2 + 4H + + 4e − Oxidation (generation of dioxygen) 4H + + 4e − → 2H 2 Reduction (generation of dihydrogen) 2H 2 O → 2H 2 + O 2 Total Reaction. Of the two half reactions, the oxidation step is the most demanding because it ...