For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature?

Question

Accepted Answer

D. 1. In a Daniell cell operating in a closed circuit, properties like electrode concentrations and the **instantaneous cell potential ($E_{	ext{cell}}$)** change as the reaction proceeds and current flows, since the Nernst equation depends on the changing reactant/product concentrations.

2. However, the **standard cell potential ($E^\circ_{	ext{cell}}$)** is defined for standard conditions (1 M concentrations, standard temperature) and is a fixed thermodynamic quantity — it does not change as time passes, since it doesn't depend on the actual instantaneous concentrations of the cell.

3. Therefore, the correct plot must show $E^\circ_{	ext{cell}}$ remaining constant over time, while any instantaneous or concentration-dependent property may vary.

Hence, the answer is **Option D**.