To determine the concentration of chloride ions Cl- in the water sample, we can use the Nernst equation, which relates the potential difference of a half-cell to the concentration of the ions involved in the redox reaction. The Nernst equation is given by:E = E - RT/nF * ln Q where:E = measured potential difference -0.45 V E = standard electrode potential 0.222 V R = gas constant 8.314 J/molK T = temperature in Kelvin 25C + 273.15 = 298.15 K n = number of electrons transferred in the half-cell reaction 1 for Ag/AgCl F = Faraday's constant 96485 C/mol Q = reaction quotient, which is the ratio of the concentrations of products to reactants [Cl-]/[Ag+] Since Ag s is a solid, its concentration is not included in the reaction quotient. Also, the concentration of Ag+ is negligible compared to Cl- because AgCl is a sparingly soluble salt. Therefore, Q can be approximated as [Cl-].Now, we can rearrange the Nernst equation to solve for [Cl-]:ln [Cl-] = E - E * nF/RT [Cl-] = exp E - E * nF/RT Plugging in the given values:[Cl-] = exp -0.45 - 0.222 * 1 * 96485 / 8.314 * 298.15 [Cl-] = exp -0.672 * -22859.7 [Cl-] 1.07 10^-3 MTherefore, the concentration of chloride ions Cl- in the water sample is approximately 1.07 10^-3 M.