To calculate the resistance of the electrochemical cell, we can use the Nernst equation and Ohm's law. First, let's find the standard cell potential E for the Cu2+/Cu and Zn2+/Zn redox couples.Cu2+ + 2e- -> Cu E = +0.34 V Zn2+ + 2e- -> Zn E = -0.76 V The overall cell reaction is:Cu2+ + Zn -> Cu + Zn2+The standard cell potential Ecell is the difference between the reduction potentials of the two half-reactions:Ecell = E Cu2+/Cu - E Zn2+/Zn = 0.34 V - -0.76 V = 1.1 VNow, we can use the Nernst equation to find the cell potential Ecell at the given concentrations:Ecell = Ecell - RT/nF * ln Q where R is the gas constant 8.314 J/ molK , T is the temperature in Kelvin assume room temperature, 298 K , n is the number of electrons transferred 2 for both Cu2+ and Zn2+ , F is the Faraday constant 96485 C/mol , and Q is the reaction quotient.Since the concentrations of both Cu2+ and Zn2+ are 0.1 M, the reaction quotient Q is:Q = [Zn2+]/[Cu2+] = 0.1/0.1 = 1Now, we can plug in the values into the Nernst equation:Ecell = 1.1 V - 8.314 J/ molK * 298 K / 2 * 96485 C/mol * ln 1 Ecell = 1.1 V - 0 = 1.1 VHowever, the electrochemical sensor measures 2.5 volts for the cell. This means there is an additional voltage Vextra due to the resistance in the cell:Vextra = Vmeasured - Ecell = 2.5 V - 1.1 V = 1.4 VNow, we can use Ohm's law to find the resistance Rcell of the electrochemical cell:Vextra = Rcell * IWe need to find the current I in the cell. We can use the cell potential Ecell and the number of electrons transferred n to find the current:I = n * F * Ecell / Ecell I = 2 * 96485 C/mol * 1.1 V / 1.1 V = 192970 C/molNow, we can plug the current I into Ohm's law to find the resistance Rcell :1.4 V = Rcell * 192970 C/molRcell = 1.4 V / 192970 C/mol 7.25 10^-6 The resistance of the electrochemical cell is approximately 7.25 10^-6 .