Question

In $H_2-O_2$ fuel cell the reaction occuring at cathode is:

• A. $2H_{2}O+O_2+4e^{-}\to 4O{H}^{-}$
• B. $2H_2+O_2\to 2H_{2}O\left(l\right)$
• C. $H^{+}+O{H}^{-}\to H_{2}O$
• D. $H^{+}+e^{-}\to \frac{1}{2}{H}_2$

Answer 1

The correct option is A $2H_{2}O+O_2+4e^{-}\to 4O{H}^{-}$

In $H_2-O_2$ fuel cell, hydrogen is oxidised at the anode and oxygen is reduced at the cathode. The half cell reactions are
At anode: $2O{H}^{-}+H_2\to 2H_{2}O+2e^{-}$
At cathode : $2H_{2}O+O_2+4e^{-}\to 4O{H}^{-}$