9.8.A—Explain the relationship between the physical components of an electrochemical cell and the overall operational…

Explain the relationship between the physical components of an electrochemical cell and the overall operational principles of the cell.

• Each component of an electrochemical cell (electrodes, solutions in the half-cells, salt bridge, voltage/current measuring device) plays a specific role in the overall functioning of the cell. The operational characteristics of the cell (galvanic vs. electrolytic, direction of electron flow, reactions occurring in each half-cell, change in electrode mass, evolution of a gas at an electrode, ion flow through the salt bridge) can be described at both the macroscopic and particulate levels.
• Galvanic, sometimes called voltaic, cells involve a thermodynamically favored reaction, whereas electrolytic cells involve a thermodynamically unfavored reaction. Visual representations of galvanic and electrolytic cells are tools of analysis to identify where half-reactions occur and in what direction current flows.
• For all electrochemical cells, oxidation occurs at the anode and reduction occurs at the cathode.
  • Exclusion: Labeling an electrode as positive or negative will not be assessed on the AP Exam.