The thermodynamic efficiency () of a fuel cell operating under standard conditions is theoretically — Electrochemistry Chemistry Question
Question
The thermodynamic efficiency ($\eta$) of a fuel cell operating under standard conditions is theoretically defined by the ratio of useful electrical work extracted to the heat of combustion of the fuel. Which mathematical expression represents this theoretical efficiency?
💡 Solution & Explanation
The useful electrical work that can be extracted from an electrochemical system is given by the standard Gibbs free energy change ($\Delta G^\circ$). The total thermal energy available from the combustion of the fuel is the standard enthalpy of combustion ($\Delta H^\circ$). Therefore, the thermodynamic efficiency is defined as $\eta = \frac{\Delta G^\circ}{\Delta H^\circ}$.