Electrical Potential

Not all redox reactions are spontaneous. There are reactions that occur spontaneously, and non-spontaneously. Non-spontaneous reactions will require more energy for them to react (e.g. electricity from an external source).

We can use electrical potential to predict a redox reactions tendency to spontaneously reaction.

Every half reaction has its own voltage.

The reduction potential table shows the reduction potential for each reduction half reaction. For the oxidation potential, simply reverse the positive or negative signage of the reduction potential. The overall voltage of a redox reaction will be the sum of the oxidation potential and reduction potential of 2 half reactions. This value can then be used to determine if the reaction will be spontaneous.