Calculating Exchange Current Density, ac, and k from Tafel Curve

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SUMMARY

The discussion focuses on calculating the exchange current density (Io), the cathodic transfer coefficient (ac), and the rate constant (k) from a Tafel curve. The user correctly identifies that the exchange current density corresponds to the y-intercept of the plot of ln(I/A) versus E/mV, while the cathodic transfer coefficient is derived from the gradient of the line. The equation ln(I) = ln(Io) + (1-ac) x nF/RT is utilized to calculate the rate constant k, confirming the importance of using the natural logarithm for accurate results.

PREREQUISITES
  • Understanding of electrochemical kinetics
  • Familiarity with Tafel plots and their interpretation
  • Knowledge of the Nernst equation and its components
  • Proficiency in logarithmic functions, specifically natural logarithms
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  • Study the derivation and applications of the Tafel equation in electrochemistry
  • Learn about the significance of exchange current density in electrochemical reactions
  • Explore the relationship between transfer coefficients and reaction mechanisms
  • Investigate the impact of temperature and concentration on rate constants in electrochemical systems
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Electrochemists, chemical engineers, and students studying electrochemical kinetics who are looking to deepen their understanding of Tafel curves and reaction rate calculations.

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Homework Statement



After plotting log(I/A) vs E/mV, you get a tafel curve. calculate the exchange current density, Io, the cathodic transfer coefficient ac and the rate constant of the reaction k.

Homework Equations





The Attempt at a Solution



Is it simply, the exchange current density is e(y intercept)

cathodic transfer coeffiecent, the gradient of the line

And then putting those two into the following quation to get K

lnI = lnIo + (1-ac) x nF/RT

Thanks for your help!
 
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I think it's ln(I/A) not log, so it's not actually a tafel curve it's a straight line.

Does this make it work?
 

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