Write the balanced half reaction that occurs at the anode in a hydrogen-oxygen fuel cell in which an acidic electrolyte is used.

Question

Write the balanced half reaction that occurs at the anode in a hydrogen-oxygen fuel cell in which an acidic electrolyte is used.

anode half-reaction: ?

Answer 1

In a hydrogen-oxygen fuel cell, H₂ is oxidized and O₂ is reduced. Since the question asks only for the half reaction at the anode, that would be the oxidation of hydrogen gas:

H₂(g) ==> 2H⁺(aq) + 2e-

It may also be seen written as

2H₂(g) ==> 4H⁺(aq) + 4e-