Chemistry
Chemistry
Problem
A galvanic cell is constructed using a Pt|Fe^{3+}(aq),Fe^{2+}(aq) half-cell (all species 1.0 M) and a Pt|Ag^{+}(aq),Ag(s) half-cell (Ag^{+} 1.0 M). The half-cells are joined by a salt bridge containing KCl(aq). After the cell has operated for several minutes at constant temperature, which change will most likely be observed in the silver half-cell? a) The concentration of Cl^{−} decreases as these anions migrate out of the compartment. b) The mass of the silver electrode decreases as Ag atoms are oxidized to . c) The concentration of K^{+} increases because these cations migrate into the compartment. d) The concentration of Ag^{+} increases because reduction occurs at the anode.Intuitive explanation
In a galvanic cell, the half-cell with the higher reduction potential acts as the cathode where reduction occurs. Silver's reduction potential is much higher than iron's, so will be reduced to solid silver metal at the cathode. As this happens, ions are consumed from solution, their concentration decreases, and solid silver deposits on the electrode—you'll see the electrode gain mass and the solution become less concentrated in silver ions.
Intuitive explanation
In a galvanic cell, the half-cell with the higher reduction potential acts as the cathode where reduction occurs. Silver's reduction potential is much higher than iron's, so will be reduced to solid silver metal at the cathode. As this happens, ions are consumed from solution, their concentration decreases, and solid silver deposits on the electrode—you'll see the electrode gain mass and the solution become less concentrated in silver ions.