A concentration cell is constructed by using the same half-reaction for both the cathode and anode.What is the cell potential for a concentration cell that combines silver electrodes in contact with 0.25 M silver nitrate and 5.0 * 10^-4 M silver nitrate solutions?
(E °= +0.80 V for Ag/Ag⁺)

Question

Quizplus · Accepted Answer

The Nernst equation for a concentration cell is:E = E° - (RT/nF)ln(Q)where:E is the cell potentialE° is the standard cell potentialR is the gas constant (8.314 J/mol·K)T is the temperature in Kelvinn is the number of moles of electrons transferred in the cell reactionF is the Faraday constant (96,485 C/mol)Q is the reaction quotientIn this case, the half-reaction for both the cathode and anode is:Ag+ + e- → AgSo, n = 1. The reaction quotient is:Q = [Ag+]/[Ag+] = 0.25 M / 5.0 M = 0.05Substituting these values into the Nernst equation, we get:E = 0.80 V - (8.314 J/mol·K * 298 K / 1 mol * 96,485 C/mol)ln(0.05) = 0.16 VTherefore, the correct answer is A.

A Concentration Cell Is Constructed by Using the Same Half-Reaction