JEE Main · 2024 · 08 Apr 2024 · Shift 2 · Redox Reactions and Electrochemistry

To determine the correct cell representation, we need to identify the half-reactions:

Anodic half-cell (oxidation):

This is a gas-ion electrode (hydrogen electrode).

Cathodic half-cell (reduction):

This is a metal-metal insoluble salt electrode.

For the overall reaction to produce ${\mathrm{H}}^{+}$ and ${\mathrm{Cl}}^{-}$ ions, we need:

• A source of ${\mathrm{Cl}}^{-}$ ions in the electrolyte (KCl or HCl)
• ${\mathrm{AgCl}}_{(\mathrm{s})}$ at the cathode

The correct cell representation is:


Option (1) with HCl would also work chemically, but option (3) with KCl is the standard representation for this type of cell (calomel-type electrode). The key is that we need ${\mathrm{Cl}}^{-}$ ions in solution and ${\mathrm{AgCl}}_{(\mathrm{s})}$ at the silver electrode.

Therefore, the correct answer is option (3).