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| The '''Warburg coefficient''' (or Warburg constant), <math>A_W</math>, is the diffusion coefficient of ions in solution, associated to the [[Warburg element]], <math>Z_W</math>. The Warburg coefficient, <math>A_W</math>, also written as, <math>{\sigma}</math>, has the units of <math>{\Omega}/\sqrt{seconds}={\Omega}(s^{-1/2})</math>
| | My name is Damion and I am studying International Relations and Nutritional Sciences at Lake Kemp / United States.<br><br>my web blog; [http://youtu.be/DOYXwofZLos pembesar payudara] |
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| The value of <math>A_W</math> can be obtained by the gradient of the Warburg plot, a linear plot of the real impedance (<math>R</math>) against the reciprocal of the square root of the frequency (<math>{1}/\sqrt{\omega}</math>). This relation should always yield a straight line, as it is unique for a Warburg.
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| Alternatively, the value of <math>A_W</math> can be found by:
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| <math>A_W={\frac{R T}{An^2F^2\sqrt2}}{\left(\frac{1}{D_O^{1/2}C_O^b}+{\frac{1}{D_R^{1/2}C_R^b}}\right)}=\frac{R T}{An^2F^2\Theta C\sqrt{2D}}</math>
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| where <math>R</math> is the [[ideal gas constant]], <math>T</math> is the [[thermodynamic temperature]], <math>F</math> is the [[Faraday constant]], <math>n</math> is the [[valence (chemistry)|valency]], <math>D</math> is the diffusion coefficient of the species where subscripts <math>O</math> and <math>R</math> stand for the oxidized and reduced species respectively, <math>C^b</math> is the concentration of the <math>O</math> and <math>R</math> species in the bulk, C is the concentration of the electrolyte, <math>A</math> denotes the surface area and <math>\Theta</math> denotes the fraction of the <math>R</math> and <math>O</math> species present.
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| The equation for <math>A_W</math> applies to both reversible and quasi-reversible reactions for which both halves of the couple are soluble.
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| ==References==
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| * A. Ottova-Leitmannova, Advances in Planar Lipid Bilayers and Liposomes, Academic Press (2006)
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| * http://www.consultrsr.com/resources/eis/warburg2.htm#ref1
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| [[Category:Electrochemistry]]
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My name is Damion and I am studying International Relations and Nutritional Sciences at Lake Kemp / United States.
my web blog; pembesar payudara