Question

In which cell does the following reaction take place? \[2H_2(g) + O_2(g) \rightarrow 2H_2O(l)\]

• A. Lead accumulator battery
• B. Fuel cell
• C. Dry cell
• D. None of these

Hint:

A cell fed continuously with \(H_2\) and \(O_2\) gases producing only water is a fuel cell.

Answer 1

The Correct Option is B

Step 1: Classify by the reactants. The reactants are the gases \(H_2\) and \(O_2\), which are the classic fuels of a fuel cell, not the solid electrode materials of ordinary batteries.
Step 2: How it works. In the \(H_2\)-\(O_2\) fuel cell, hydrogen is oxidised at one electrode and oxygen is reduced at the other; the only product is water and electrical energy is delivered as long as the gases keep flowing.
Step 3: Compare devices. A lead storage battery is rechargeable using lead plates; a dry cell is a one-shot zinc-carbon device. Neither converts \(H_2\) and \(O_2\) into water.
Step 4: Answer. The given reaction is the working reaction of a fuel cell.
\[\boxed{\text{Fuel cell}}\]