Electrode potentials

This chapter discusses electrode potentials. Each electrode can be considered to make a characteristic contribution to the overall cell potential. The standard potential of a couple is the potential of a cell in which the couple forms the right-hand electrode and the left-hand electrode is a standard hydrogen electrode, all species being present at unit activity. The electrochemical series lists the metallic elements in the order of their reducing power as measured by their standard potentials in aqueous solution: low reduces high. The chapter then explains how the difference of the cell potential from its standard value is used to measure the activity coefficient of ions in solution. Meanwhile, standard potentials are used to calculate the standard cell potential and then to calculate the equilibrium constant of the cell reaction.