CBSE Class 12-science Answered

Overpotential here is referring to the potential difference or voltage) between a half-reaction reduction potential and the potential at which the redox reaction is experimentally observed.

In redox reactions, there can be four possible polarities of overpotentials which are listed below.

Due to overpotential:

• An electrolytic cell's anode is more positive which means it uses more energy than its thermodynamics require.
• An electrolytic cell's cathode is more negative which signifies it uses more energy than thermodynamics require.
• A galvanic cell's anode is less negative which means it supplies less energy than thermodynamically possible.
• A galvanic cell's cathode is less positive which means it supplies less energy than thermodynamically possible.