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In generic terms, electrochemical potential is the mechanical work done in bringing 1 mole of an ion from a standard state to a specified concentration and electrical potential. According to the IUPAC definition, [4] it is the partial molar Gibbs energy of the substance at the specified electric potential, where the substance is in a specified ...
Bipolar electrochemistry scheme. In electrochemistry, standard electrode potential, or , is a measure of the reducing power of any element or compound.The IUPAC "Gold Book" defines it as; "the value of the standard emf (electromotive force) of a cell in which molecular hydrogen under standard pressure is oxidized to solvated protons at the left-hand electrode".
To avoid possible ambiguities, the electrode potential thus defined can also be referred to as Gibbs–Stockholm electrode potential. In both conventions, the standard hydrogen electrode is defined to have a potential of 0 V. Both conventions also agree on the sign of E for a half-cell reaction when it is written as a reduction.
The data below tabulates standard electrode potentials (E°), in volts relative to the standard hydrogen electrode (SHE), at: . Temperature 298.15 K (25.00 °C; 77.00 °F); ...
References and notes CH 3 COOH + 2H + + 2e − → CH 3 CHO + H 2 O: −0.58 Many carboxylic acid: aldehyde redox reactions have a potential near this value 2 H + + 2 e − → H 2: −0.41 Non-zero value for the hydrogen potential because at pH = 7, [H +] = 10 −7 M and not 1 M as in the standard hydrogen electrode (SHE), and that: E red = -0 ...
i.e., the external potential is the sum of electric potential, gravitational potential, etc. (where q and m are the charge and mass of the species, V ele and h are the electric potential [15] and height of the container, respectively, and g is the acceleration due to gravity). The internal chemical potential includes everything else besides the ...
It uses a dimensionless potential = and the lengths are measured in units of the Debye electron radius in the region of zero potential = (where denotes the number density of negative ions in the zero potential region). For the spherical case, L=2, the axial case, L=1, and the planar case, L=0.
The electric potential and the magnetic vector potential together form a four-vector, so that the two kinds of potential are mixed under Lorentz transformations. Practically, the electric potential is a continuous function in all space, because a spatial derivative of a discontinuous electric potential yields an electric field of impossibly ...