The standard cell potential (E_ cell ^ ) of a fuel cell based on …

MCQ

The standard cell potential $\left(\mathrm{E}_{\text {cell }}^{\ominus}\right)$ of a fuel cell based on the oxidation of methanol in air that has been used to power television relay station is measured as 1.21 V . The standard half cell reduction potential for $\mathrm{O}_{2}\left(\mathrm{E}_{\mathrm{O}_{2} / \mathrm{H}_{2} \mathrm{O}}^{\mathrm{O}}\right)$ is 1.229 V .
Choose the correct statement:

A
The standard half cell reduction potential for the reduction of $\mathrm{CO}_{2}\left(\mathrm{E}_{\mathrm{CO}_{2} / \mathrm{CH}_{3} \mathrm{OH}}^{0}\right)$ is 19 Mv
B
Oxygen is formed at the anode.
C
Reactants are fed at one go to each electrode.
D
Reduction of methanol takes place at the cathode.

✓

Answer

A. The standard half cell reduction potential for the reduction of $\mathrm{CO}_{2}\left(\mathrm{E}_{\mathrm{CO}_{2} / \mathrm{CH}_{3} \mathrm{OH}}^{0}\right)$ is 19 mV
$\because \mathrm{E}_{\text {cell }}^{\mathrm{o}}=\mathrm{E}_{\text {cathode }}^{\mathrm{o}}-\mathrm{E}_{\text {Anode }}^{\mathrm{o}}$
$1.21=1.229- E _{\text {Anode }}^{ o }$
$\because$ Fuel cell involves oxidation of methanol which will occur at anode and reduction of $\mathrm{O}_{2}$ will occur at cathode.