Partial current

In electrochemistry, partial current is defined as the electric current associated with (anodic or cathodic) half of the electrode reaction. Depending on the electrode half-reaction, one can distinguish two types of partial current: * cathodic partial current I c (called also cathodic current): is the flow of electrons from the electrode surface to a species in solution; * anodic partial current I a (called also anodic current): is the flow of electrons into the electrode from a species in solution. The cathodic and anodic partial currents are defined by IUPAC. The partial current densities (i c and i a ) are the ratios of partial currents respect to the electrode areas (A c and A a ): :i c = I c /A c :i a = I a /A a The sum of the cathodic partial current density i c (positive) and the anodic partial current density i a (negative) gives the net current density i: :i = i c + i a In the case of the cathodic partial current density being equal to the anodic partial current density (for example, in a corrosion process ), the net current density on the electrode is zero: :i eq = i c,eq + i a,eq = 0 When more than one reaction occur on an electrode simultaneously, then the total electrode current can be expressed as: : I = \Sigma I_{a,j} + \Sigma I_{c,j} where the index j refers to the particular reactions.

In electrochemistry, partial current is defined as the electric current associated with (anodic or cathodic) half of the electrode reaction. Depending on the electrode half-reaction, one can distinguish two types of partial current: cathodic partial current I c (called also cathodic current): is the flow of electrons from the electrode surface to a species in solution; anodic partial current I a (called also anodic current): is the flow of electrons into the electrode from a species in solution. The cathodic and anodic partial currents are defined by IUPAC. The partial current densities (i c and i a ) are the ratios of partial currents respect to the electrode areas (A c and A a ): i c = I c /A c i a = I a /A a The sum of the cathodic partial current density i c (positive) and the anodic partial current density i a (negative) gives the net current density i: i = i c + i a In the case of the cathodic partial current density being equal to the anodic partial current density (for example, in a corrosion process ), the net current density on the electrode is zero: i eq = i c,eq + i a,eq = 0 When more than one reaction occur on an electrode simultaneously, then the total electrode current can be expressed as: I = \Sigma I_{a,j} + \Sigma I_{c,j} where the index j refers to the particular reactions. ==Notes== ==See also== Exchange current density

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