Galvanic Cells Quiz

PDF page 911: As demonstration of spontaneous chemical change, Figure 17.2 shows the result of immersing a coiled wire of copper into an aqueous solution of silver nitrate. A gradual but visually impressive change spontaneously occurs as the initially colorless solution becomes increasingly blue, and the initially smooth copper wire becomes covered with a porous gray solid.

PDF page 911: These observations are consistent with (i) the oxidation of elemental copper to yield copper(II) ions, Cu (aq), which impart a blue color to the solution, and (ii) the reduction of silver(I) ions to yield elemental silver, which deposits as a fluffy solid on the copper wire surface. And so, the direct transfer of electrons from the copper wire to the aqueous silver ions is spontaneous under the employed conditions. A summary of this redox system is provided by these equations:

PDF page 911: These observations are consistent with (i) the oxidation of elemental copper to yield copper(II) ions, Cu (aq), which impart a blue color to the solution, and (ii) the reduction of silver(I) ions to yield elemental silver, which deposits as a fluffy solid on the copper wire surface. And so, the direct transfer of electrons from the copper wire to the aqueous silver ions is spontaneous under the employed conditions. A summary of this redox system is provided by these equations:

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: inert electrolyte solution called a salt bridge. The spontaneous reaction in this cell produces Cu cations in the anode

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: + 2 + overall reaction: Cu(s) + 2Ag (aq) ⟶ Cu (aq) + 2Ag(s) 2+ − oxidation half-reaction: Cu(s) ⟶ Cu (aq) + 2e + − reduction half-reaction: 2Ag (aq) + 2e ⟶ 2Ag(s) Consider the construction of a device that contains all the reactants and products of a redox system like the one here, but prevents physical contact between the reactants. Direct transfer of electrons is, therefore, prevented; transfer, instead, takes place indirectly through an external circuit that contacts the separated reactants. Devices of this sort are generally referred to as electrochemical cells, and those in which a spontaneous redox reaction takes place are called galvanic cells (or voltaic cells). 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 halfcell 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(I)/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

PDF page 912: bridge that maintains charge balance. Increasing concentrations of Cu in the anode half-cell are balanced by an

PDF page 912: influx of NO3 from the salt bridge, while a flow of Na into the cathode half-cell compensates for the decreasing

PDF page 913: • By convention, the schematic begins with the anode and proceeds left-to-right identifying phases and