CH302H - Principles of Chemistry II: Honors
Spring 2016, Unique 49420

Lecture Summary, 5 April 2016

Electrochemistry: Electrochemistry is the branch of chemistry that describes the transfer of electrons from one species to another.  Today we spent a considerable amount of time going over definitions and vocabulary.  These are all in the beginning of Chap. 17 of your textbook, so please review them if you are confused.  Standard potentials for many electrochemical reactions in water have been tabulated and are listed in Appendix E of your textbook.  By convention, these values are always given for the reduction reaction and are always referenced to the standard hydrogen electrode (SHE), whose reduction potential is equal to 0 by definition.  The electric potential of the cell can be determined from the difference in the two reduction potentials of the half reactions, and the free energy of the reaction can be determined by the electric potential of the cell.  We can thus connect measured electric potentials directly to free energies and equilibrium constants of the electrochemical (often called redox) reaction.