Question

The substance reduced in a hydrogen-oxygen fuel cell is _____. oxygen hydrogen water hydrogen peroxide\

Answer 1

Answer: Oxygen

Explanation:

Answer 2

Answer: The substance which gets reduced in the hydrogen-oxygen fuel cell is oxygen.

Explanation:

A reduced substance undergoes reduction reaction. This is defined as the reaction in which an atom gains electrons.

A fuel cell is defined as the electrochemical cell which converts the chemical energy of a fuel (often used hydrogen) and an oxidizing agent (often used oxygen) into electrical energy via a pair of redox reactions.

The reactions which occur in hydrogen-oxygen fuel cell are:

At cathode:  $H_2+2OH^-\rightarrow 2H_2O+2e^-$

At anode:  $\frac{1}{2}O_2+H_2O+2e^-\rightarrow 2OH^-$

As, the oxygen is gaining electrons from the above reaction. Thus, it is undergoing reduction reaction and is getting reduced.

Hence, the substance which gets reduced in the hydrogen-oxygen fuel cell is oxygen.