To calculate the current density in an electrochemical cell, we need to use the Nernst equation and the Butler-Volmer equation. First, let's find the exchange current density i0 using the Nernst equation:E = E0 - RT/nF * ln Q where E is the cell potential, E0 is the standard cell potential, R is the gas constant 8.314 J/molK , T is the temperature in Kelvin, n is the number of electrons transferred, F is the Faraday constant 96485 C/mol , and Q is the reaction quotient.We are given E = 1.2 V, but we don't have enough information to determine E0, n, or the reaction quotient Q . Therefore, we cannot proceed with the Nernst equation.Alternatively, we can use the Butler-Volmer equation to find the current density i :i = i0 * exp a * n * F * / R * T - exp -c * n * F * / R * T where i0 is the exchange current density, a and c are the anodic and cathodic transfer coefficients, is the overpotential, and the other variables are the same as in the Nernst equation.However, we also don't have enough information to determine i0, a, c, or . Therefore, we cannot proceed with the Butler-Volmer equation either.In conclusion, we cannot calculate the current density in the electrochemical cell with the given information. We would need more information about the specific electrochemical reaction taking place, such as the standard cell potential, the number of electrons transferred, and the transfer coefficients.