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A student needs to calculate the Tafel slopes for the anodic and cathodic reactions from a given set of experimental data obtained during an electrochemical experiment. The experiment involves the corros

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To calculate the Tafel slopes for the anodic and cathodic reactions, the student should follow these steps:1. Prepare the data: The student should have a set of experimental data containing the applied potentials  E  and the corresponding anodic  i_a  and cathodic  i_c  current densities.2. Convert the applied potentials to overpotentials: The overpotential    is the difference between the applied potential  E  and the equilibrium potential  E_eq  for the reaction. For iron corrosion in an acidic solution, the standard equilibrium potential for the anodic reaction  Fe  Fe + 2e  is -0.44 V vs SHE, and for the cathodic reaction  2H + 2e  H  is 0 V vs SHE. Calculate the overpotentials for both reactions using the given applied potentials.3. Plot the Tafel plots: For each reaction, plot the overpotential    on the x-axis and the logarithm of the absolute value of the current density  log|i|  on the y-axis. You should have two separate plots: one for the anodic reaction and one for the cathodic reaction.4. Determine the Tafel slopes: For each plot, find the linear region and fit a straight line to the data points in that region. The slope of the fitted line is the Tafel slope  b  for the corresponding reaction. Calculate the Tafel slopes for both the anodic and cathodic reactions.5. Explain the corrosion mechanism: Based on the obtained Tafel slopes, the student can explain the corrosion mechanism of iron in the given acidic solution. The anodic reaction involves the oxidation of iron to form Fe ions, while the cathodic reaction involves the reduction of H ions to form hydrogen gas. The Tafel slopes can provide information about the rate-determining step and the reaction mechanism for each process. For example, if the Tafel slope for the anodic reaction is close to 120 mV/decade, it suggests that the rate-determining step is the charge transfer process. If the Tafel slope for the cathodic reaction is close to 40 mV/decade, it suggests that the rate-determining step is the diffusion of H ions to the electrode surface.By analyzing the Tafel slopes and understanding the underlying electrochemical processes, the student can gain insights into the corrosion mechanism of iron in the given acidic solution.

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