A concentration cell is constructed by using the same half-reaction for both the cathode and anode. What is the value of E_cell for a concentration cell that combines silver electrodes in contact with 0.10 M silver nitrate and 0.00003 M silver nitrate solutions? ( $E _ { \mathrm { red } } ^ { \circ }$ = +0.80 V for Ag/Ag⁺)

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Quizplus · Accepted Answer

The cell potential for a concentration cell is calculated using the Nernst equation: $ E_{cell} = E^\circ - \frac{RT}{nF} \ln \frac{[Ag^+]_{anode}}{[Ag^+]_{cathode}} $. Since $ E^\circ = 0 $ for a concentration cell, $ E_{cell} = - \frac{RT}{nF} \ln \frac{0.00003}{0.10} $. At 298 K, this simplifies to $ E_{cell} = \frac{0.0592}{1} \log \frac{0.10}{0.00003} \approx +0.21 $ V.

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A Concentration Cell Is Constructed by Using the Same Half-Reaction $E _ { \mathrm { red } } ^ { \circ }$