Final answer:
A galvanic cell based on the spontaneous reaction between copper and silver(I) is depicted. The cell is comprised of two half-cells, each containing the redox conjugate pair of a single reactant. The spontaneous reaction in this cell produces Cu²+ cations in the anode half-cell and consumes Ag+ ions in the cathode half-cell.
Step-by-step explanation:
A galvanic cell based on the spontaneous reaction between copper and silver(I) is depicted in Figure 17.3. The cell is comprised of two half-cells, each containing the redox conjugate pair ("couple") of a single reactant. The half-cell shown at the left contains the Cu(0)/Cu(II) couple in the form of a solid copper foil and an aqueous solution of copper nitrate. The right half-cell contains the Ag(1)/Ag(0) couple as solid silver foil and an aqueous silver nitrate solution. An external circuit is connected to each half-cell at its solid foil, meaning the Cu and Ag foil each function as an electrode. By definition, the anode of an electrochemical cell is the electrode at which oxidation occurs (in this case, the Cu foil) and the cathode is the electrode where reduction occurs (the Ag foil).
The redox reactions in a galvanic cell occur only at the interface between each half-cell's reaction mixture and its electrode. To keep the reactants separate while maintaining charge-balance, the two half-cell solutions are connected by a tube filled with inert electrolyte solution called a salt bridge. The spontaneous reaction in this cell produces Cu²+ cations in the anode half-cell and consumes Ag+ ions in the cathode half-cell, resulting in a compensatory flow of inert ions from the salt bridge that maintains charge balance. Increasing concentrations of Cu²+ in the anode half-cell are balanced by an influx of NO3¯ from the salt bridge, while a flow of Na+ into the cathode half-cell compensates for the decreasing Ag+ concentration.