Calculate the concentration of Cl^- ions in a solution if the electrode potential of a Pt/AgCl electrode in the solution is measured to be +0.222 V versus the standard hydrogen electrode (SHE) at 25°C. The standard electrode potential for the reaction AgCl(s) + e^- → Ag(s) + Cl^- is +0.222 V versus SHE at 25°C. Assume the activity coefficient of Cl^- ions in the solution is equal to 1.

Question

Calculate the concentration of Cl^- ions in a solution if the electrode potential of a Pt/AgCl electrode in the solution is measured to be +0.222 V versus the standard hydrogen electrode (SHE) at 25°C. The standard electrode potential for the reaction AgCl(s) + e^- → Ag(s) + Cl^- is +0.222 V versus SHE at 25°C. Assume the

Answer 1

To calculate the concentration of Cl ions in the solution, we can use the Nernst equation. The Nernst equation relates the electrode potential of a half-cell to the standard electrode potential, temperature, and concentrations  or activities  of the species involved in the redox reaction. The Nernst equation is given by:E = E -  RT/nF  * ln Q where:E = electrode potential of the half-cellE = standard electrode potentialR = gas constant  8.314 J/molK T = temperature in Kelvin  25C = 298.15 K n = number of electrons transferred in the redox reaction  1 for AgCl/Ag redox couple F = Faraday's constant  96,485 C/mol Q = reaction quotient, which is equal to the concentration of Cl ions in this caseGiven that the electrode potential  E  and the standard electrode potential  E  are both +0.222 V, the equation becomes:0.222 = 0.222 -  8.314 * 298.15 /  1 * 96,485   * ln [Cl] Solving for [Cl]:0 = -  8.314 * 298.15 / 96,485  * ln [Cl] Since the natural logarithm  ln  of 1 is 0, this equation implies that:[Cl] = 1Therefore, the concentration of Cl ions in the solution is 1 M  1 mol/L .