A voltaic cell is constructed with two silver-silver chloride electrodes,where the half-reaction is
AgCl(s) + → Ag(s) + (aq) E° = +0.222 V
The concentrations of chloride ion in the two compartments are 0.0222 mol L^-1 and 2.22 mol L^-1,respectively.The cell emf is ________ V.

Question

A voltaic cell is constructed with two silver-silver chloride electrodes,where the half-reaction is
AgCl(s) +

→ Ag(s) +

(aq) E° = +0.222 V
The concentrations of chloride ion in the two compartments are 0.0222 mol L^-1 and 2.22 mol L^-1,respectively.The cell emf is ________ V.

Quizplus · Accepted Answer

The Nernst equation can be used to calculate the cell potential when the concentrations of the reactants and products are not standard.

E = E° - (RT/nF)ln(Q)

Where E = cell emf, E° = standard cell potential, R = gas constant, T = temperature in Kelvin, n = moles of electrons transferred, F = Faraday constant, and Q = reaction quotient.

In this case, the half-reaction is AgCl(s) + e- → Ag(s) + Cl-(aq), so n = 1.

At the anode (left side), Q = [Ag+][Cl-]/[AgCl] = (1×10^-2)(0.0222)/(1) = 2.22×10^-4.

At the cathode (right side), Q = [Ag+][Cl-]/[AgCl] = (1×10^-2)(2.22)/(1) = 0.222.

Plugging in the values, we get:

E = 0.222 V - (0.0257 V/K)(298 K)/1 × ln(0.222/2.22×10^-4)

E = 0.118 V

Therefore, the answer is B.

A Voltaic Cell Is Constructed with Two Silver-Silver Chloride Electrodes,where