A fuel cell designed to react grain alcohol with oxygen has the following net reaction:
C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l)
The maximum work that 1 mol of alcohol can yield by this process is 1320 kJ. What is the theoretical maximum voltage this cell can achieve?

Question

Quizplus · Accepted Answer

The maximum work that 1 mol of alcohol can yield by this process is 1320 kJ. The theoretical maximum voltage this cell can achieve is:E° = -ΔG°/nFwhere ΔG° is the standard free energy change for the reaction, n is the number of moles of electrons transferred, and F is the Faraday constant.ΔG° = -1320 kJ/mol = -1320000 J/moln = 6 (3 moles of electrons transferred for each mole of alcohol)F = 96485 C/molE° = -(-1320000 J/mol) / (6 mol * 96485 C/mol) = 2.28 VTherefore, the theoretical maximum voltage this cell can achieve is 2.28 V.

A Fuel Cell Designed to React Grain Alcohol with Oxygen