Consider a generic redox reaction that transfers moles of electrons per mole of…

CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry

Problem

Consider a generic redox reaction that transfers nn moles of electrons per mole of reaction under standard conditions at temperature TT. Useful constants: Faraday constant F=9.65×104 C mol−1F = 9.65 \times 10^{4}\,\text{C mol}^{-1} Gas constant R=8.314 J mol−1K−1R = 8.314\,\text{J mol}^{-1}\text{K}^{-1} (a) Starting from fundamental thermodynamic relationships, derive an expression that relates log⁡10K\log_{10} K (base-10 logarithm of the equilibrium constant) to the standard potential E°E°, the number of electrons nn, and temperature TT. Express your final equation explicitly in terms of numerical constants and the variables E°E°, nn, and TT. (b) A redox reaction transferring n=3n = 3 electrons per reaction unit has a standard potential of E°=+0.15 VE° = +0.15\,\text{V} at 298 K. Use the expression derived in part (a) to calculate the equilibrium constant for this reaction. Report the answer in scientific notation. (c) Discuss how the equilibrium constant would change qualitatively if the standard potential remained the same but the number of electrons transferred doubled. Provide reasoning based on your derived equation.

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