At equilibrium

Options

A. a cell operates first reversibly and then irreversibly
B. the cell potential is negative
C. the cell potential is positive
D. a cell is exhausted

Answer

D

Explanation

As the cell discharges and current flows, the product concentrations increase. At the same time, reactant concentrations increase. This increases `log Q_("cell")`,, so the cor-reaction factor becomes more negative. Thus, the overall `E_("cell")` decreases (the reaciton becomes less favourable). Eventually the cell potential approaches zero (equilibrium) and the cell "run down". The cell is completly run down `(E_("cell") = 0)`. when the cell term `(0.0592)/(n) log Q_("cell")` is equal in magnitude to `E_("cell")^(@)` . At equilibrium the reaction quotient `(Q)` is equal to the equalirium constant `(K_(eq))`.