To calculate the activation energy Ea for the electrochemical reaction between copper and zinc ions in a copper-zinc galvanic cell, we can use the Arrhenius equation:k = A * exp -Ea / R * T where k is the rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant 8.314 J/molK , and T is the temperature in Kelvin 25C = 298.15 K .However, we need to relate the rate constant k to the potential difference 1.8 V in the galvanic cell. We can do this using the Butler-Volmer equation:i = i0 * exp * F * / R * T - exp - 1 - * F * / R * T where i is the current, i0 is the exchange current density, is the charge transfer coefficient, F is the Faraday constant 96485 C/mol , is the overpotential, and the other variables are as previously defined.In a galvanic cell, the potential difference 1.8 V is equal to the difference between the standard reduction potentials of the two half-reactions:E_cell = E_cathode - E_anodeFor a copper-zinc galvanic cell, the standard reduction potentials are:E_cathode Cu + 2e Cu = +0.34 VE_anode Zn Zn + 2e = -0.76 VE_cell = 0.34 V - -0.76 V = 1.1 VSince the potential difference in the given problem is 1.8 V, which is higher than the standard potential difference 1.1 V , we have an overpotential of: = 1.8 V - 1.1 V = 0.7 VNow, we need to find the relationship between the rate constant k and the current i or the exchange current density i0 . This relationship is not straightforward and depends on the specific reaction kinetics and the electrode surface properties. Therefore, without further information, it is not possible to accurately calculate the activation energy Ea for this electrochemical reaction.