To calculate the corrosion current density i_corr of the copper metal in the galvanic couple, we need to use the Butler-Volmer equation. The Butler-Volmer equation is given by:i = i_corr * exp E - E_corr / a * Tafel_slope - exp - E - E_corr / c * Tafel_slope where:i = current densityE = open circuit potential 0.34 V E_corr = corrosion potential unknown a = anodic Tafel constant assumed to be 1 c = cathodic Tafel constant assumed to be 1 Tafel_slope = 120 mV/decadeHowever, we don't have enough information to directly calculate the corrosion current density using the Butler-Volmer equation. We need the corrosion potential E_corr and the exchange current density i0 to solve the equation.In order to find E_corr, we would need more information about the electrochemical system, such as the standard reduction potentials of the copper and silver electrodes. Similarly, the exchange current density i0 would require additional information about the reaction kinetics.Without these values, it is not possible to calculate the corrosion current density of the copper metal in the galvanic couple with the given information.