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The Koutecký–Levich equation models the measured electric current at an 
The Koutecký–Levich equation can be written as'':''
where
* ''i''m is the measured current (A).
* ''i''K is the kinetic current (A) from the electrochemical reactions.
* ''i''MT is the
where:
* ''B''L is the Levich Constant.
* ''ω'' is the angular rotation rate of the electrode (rad/s)
From an experimental data set where the current is measured at different rotation rates, it is possible to extract the kinetic current from a so-called Koutecký–Levich plot. In a Koutecký–Levich plot the inverse measured current is plotted versus the inverse square root of the rotation rate. This will linearize the data set and the inverse of the kinetic current can be obtained by extrapolating the line to the
electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials d ...
from an electrochemical reaction
Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outco ...
in relation to the kinetic activity and the mass transport
Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typica ...
of reactants.
The Koutecký–Levich equation can be written as'':''
where
* ''i''m is the measured current (A).
* ''i''K is the kinetic current (A) from the electrochemical reactions.
* ''i''MT is the mass transport
Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typica ...
current (A).
Note the similarity of this equation to the conductance of an electrical circuits in parallel.
The Koutecký–Levich equation is also commonly expressed as:
The kinetic current (''i''K) can be modeled by the Butler-Volmer Equation and is characterized by being potential dependent. On the other hand, the mass transport current (''i''MT) depends on the particular electrochemical setup and amount of stirring.
Koutecký–Levich plot
In the case a rotating disk electrode setup is used and the electrode is flat and smooth, the ''i''MT can modeled using the Levich equation. Inserted in the Koutecký–Levich equation, we get:
where:
* ''B''L is the Levich Constant.
* ''ω'' is the angular rotation rate of the electrode (rad/s)
From an experimental data set where the current is measured at different rotation rates, it is possible to extract the kinetic current from a so-called Koutecký–Levich plot. In a Koutecký–Levich plot the inverse measured current is plotted versus the inverse square root of the rotation rate. This will linearize the data set and the inverse of the kinetic current can be obtained by extrapolating the line to the ordinate
In common usage, the abscissa refers to the (''x'') coordinate and the ordinate refers to the (''y'') coordinate of a standard two-dimensional graph.
The distance of a point from the y-axis, scaled with the x-axis, is called abscissa or x c ...
. This y-intercept corresponds to taking the rotation rate up to infinity, where the reaction is not mass-transport limited. Koutecký–Levich analysis is therefore used to determine the kinetic constants of the reaction such as the kinetic constant and the symmetry factor .
References