Redox Reactions and Electrochemical Cells
Some electrochemical cells permit a half-redox reaction to occur separately but obligatorily simultaneously with another half-redox reaction. This is not possible with redox reactions taking place within a solution. In this case, it is impossible to separate the two half-reactions into which the global reaction can be decomposed. This possibility, which comes from using electrochemical cells, permits us to quantify the oxidizing strength of redox couples through the concept of standard potentials. This is achieved with the help of Nernst’s equation. Thus, predicting the direction of redox reactions and their extent is possible on the basis of thermodynamics.