Question

The efficiency of fuel cell is given by the expression, $∆\mathrm{H}$ is______

Answer 1

Efficiency:

1. The ratio of electrical free energy to reaction enthalpy change represents the fuel cell's thermodynamic efficiency.
2. It is given by$\mathrm{\eta }=\frac{-{\mathrm{nFE}}_{\mathrm{cell}}}{∆\mathrm{H}}\times 100$ where n is number of electrons transferred during the reaction, F is the faraday constant, and ${\mathrm{E}}_{\mathrm{cell}}$ is cell potential.
3. Also, The ratio of the Gibbs function change to the Enthalpy change in the total cell reaction determines the fuel cell's thermodynamic efficiency
4. It is given by $\mathrm{\eta }=\frac{∆\mathrm{G}}{∆\mathrm{H}}\times 100$
5. The electrical work is measured by the Gibbs function change, and the heating value of the fuel is measured by the enthalpy change.
6. A cell with high efficiency is referred to because they produce more energy than a normal cell.

Therefore, the efficiency of the fuel cell is given by the expression, $∆\mathrm{H}$ is the enthalpy change