Question

Which of the following cell reactions is exhibited by fuel cell?

• A. \(\text{Cd}_{(s)}+2\text{Ni(OH)}_{3(s)}\rightarrow \text{CdO}_{(s)}+2\text{Ni(OH)}_{2(s)}+2\text{H}_{2}\text{O}_{(l)}\)
• B. \(\text{Pb}_{(s)}+\text{PbO}_{2(s)}+2\text{H}_{2}\text{SO}_{4(aq)}\rightarrow 2\text{PbSO}_{4(s)}+2\text{H}_{2}\text{O}_{(l)}\)
• C. \(2\text{H}_{2(g)}+\text{O}_{2(g)}\rightarrow 2\text{H}_{2}\text{O}_{(l)}\)
• D. \(2\text{Fe}_{(s)}+\text{O}_{2}+4\text{H}^{+}\rightarrow 2\text{Fe}_{(aq)}^{2+}+2\text{H}_{2}\text{O}_{(l)}\)

Hint:

A fuel cell converts the combustion energy of hydrogen and oxygen directly into electricity.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
A fuel cell turns the energy of combustion of a fuel such as hydrogen directly into electricity.

Step 2: Hydrogen-oxygen cell
Hydrogen is oxidised at the anode and oxygen is reduced at the cathode. The net reaction is \(2\text{H}_{2}+\text{O}_{2}\rightarrow 2\text{H}_{2}\text{O}\).

Step 3: Other reactions
Option A is the Ni-Cd cell.
Option B is the lead accumulator.
Option D is the rusting of iron.

Final Answer:
The fuel cell reaction is hydrogen plus oxygen giving water. \[ \boxed{\text{(C) }2\text{H}_{2(g)}+\text{O}_{2(g)}\rightarrow 2\text{H}_{2}\text{O}_{(l)}} \]