what happens in a hydrogen-oxygen fuel cell?
a. oxygen diffuses through the cathode
b. oxygen diffuses through the anode
c. hydrogen diffuses through the anode
d. hydrogen and oxygen are mixed before entering the anode

Answer : The correct option is, (B) Oxygen diffuses through the anode.

Explanation :

Hydrogen-oxygen fuel cell : As we know that the a fuel cell is a type of device that converts the chemical energy into electrical energy. In the hydrogen-oxygen fuel cell, the proton exchange membrane cell uses hydrogen and oxygen gas as a fuel.

In this cell reaction, hydrogen and oxygen gas are the reactants and water, electricity and heat are the products.

The half-cell electrode reaction are:

At anode :

At cathode :

That means the hydrogen undergoes reduction at anode and oxygen undergoes oxidation at cathode.

As per question, we can say that oxygen diffuses towards anode and hydrogen diffuses towards cathode.

Hence, the correct option is, (B) Oxygen diffuses through the anode.