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Calculate the polarization resistance of a copper electrode in a 0.1 M copper sulfate solution at 25°C, given that the current density is 10 mA/cm² and the exchange current density is 0.1 mA/cm². The Tafel slope is 30 mV/decade.

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To calculate the polarization resistance  Rp  of the copper electrode, we can use the following equation:Rp =  dE/di  =  Tafel slope  /  n * F * exchange current density where dE is the change in potential, di is the change in current density, n is the number of electrons transferred in the reaction  n = 2 for copper , F is the Faraday constant  F = 96485 C/mol , and the exchange current density is given as 0.1 mA/cm.First, we need to convert the Tafel slope from mV/decade to V/decade:Tafel slope = 30 mV/decade *  1 V/1000 mV  = 0.03 V/decadeNext, we need to find the overpotential    using the Tafel equation: = Tafel slope * log10 current density / exchange current density  = 0.03 V/decade * log10 10 mA/cm / 0.1 mA/cm  = 0.03 V/decade * log10 100  = 0.03 V/decade * 2 = 0.06 VNow we can calculate the polarization resistance:Rp =  dE/di  =  Tafel slope  /  n * F * exchange current density Rp =  0.06 V  /  2 * 96485 C/mol * 0.1 mA/cm *  1 A/1000 mA  *  1 mol/96485 C  Rp =  0.06 V  /  2 * 0.1 A/cm Rp = 0.06 V / 0.2 A/cmRp = 0.3 cmThe polarization resistance of the copper electrode in a 0.1 M copper sulfate solution at 25C is 0.3 cm.

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