NEET2026ChemistryChapterActual
An electrolyte concentration cell consists of two identical metallic electrodes dipped in solutions of the same electrolyte but at different concentrations. Which of the following statements correctly describes the standard cell potential ( E^ _ cell ) for such a cell?
Options
- AIt is always positive to drive the spontaneous flow of electrons.
- BIt is zero because both half-cells have the same standard reduction potential.
- CIt is determined by the ratio of the electrolyte concentrations in the two half-cells.
- DIt is negative, meaning the cell requires an external voltage to operate.
Correct answer
B. It is zero because both half-cells have the same standard reduction potential.
Step-by-step solution
For an electrolyte concentration cell, the electrodes and the electrolyte are identical in both half-cells. The standard cell potential E^ _ cell is the potential of the cell when all species are at their standard states (unit activity or 1 M concentration). Since both half-cells are identical under standard conditions, their standard reduction potentials are equal. E^ _ cell = E^ _ cathode - E^ _ anode = 0 The actual cell potential E_ cell depends on the concentration ratio according to the Nernst equation, but th