Match List I with List II:

Choose the correct answer from the options given below:

A. Leclanche Cell (Dry Cell)

The Leclanche cell is a primary cell (non-rechargeable). It consists of a zinc container that acts as the anode. The chemical reaction at the anode involves the oxidation of zinc metal into zinc ions.

• Anode Reaction: Zn(s) to Zn^{2+}(aq) + 2e^-

B. Ni - Cd Cell (Nickel-Cadmium

The Ni-Cd cell is a secondary cell, meaning the electrochemical reactions are reversible. When an external electrical current is applied in the opposite direction, the cell "recharges." It has a longer life than lead-acid batteries but is more expensive to manufacture.

C. Fuel Cell 

Unlike conventional batteries that store chemical energy, fuel cells are designed to convert the energy of combustion of fuels (like hydrogen, methane, or methanol) directly into electrical energy.

• Overall Reaction: 2H2(g) + O2(g) to 2H2O(l)

D. Mercury Cell 

The Mercury cell is used in low-current devices like hearing aids and watches. A unique property of this cell is that the overall reaction does not involve any ions in the solution whose concentration can change during life. This allows the cell to provide a constant voltage (1.35 V) throughout its entire lifespan.

• Anode: Zn(Hg) (Zinc amalgam)
• Cathode: HgO (Mercuric oxide)