What is Electrode Potential?

In each half-cell, electrons move between the electrodes through the electrolyte. This movement of charge creates a potential known as Electrode Potential. Electrode Potential can be categorized into two types: Oxidation Potential and Reduction Potential. Let’s understand each of them:

Oxidation Potential: It represents the tendency of a metal (M) to undergo oxidation by losing electrons (ne^–) and forming metal ions (Mⁿ⁺). This process is denoted as

M → Mⁿ⁺ + ne^–.

Reduction Potential: It represents the tendency of metal ions (Mⁿ⁺) to gain electrons (ne^–) and convert them back into the original metal (M). This process is denoted as

Mⁿ⁺ + ne^– → M.

Factors Affecting Electrode Potential

There are various factors affecting the electrode potential, some of those factors are as follows:

• Nature of Electrolyte: The presence and concentration of ions in the solution affect the activity or effective concentration of the species involved in the redox reaction, thus impacting the electrode potential.
• Temperature: As temperature increases, the kinetic energy of the reacting species also increases, leading to faster reaction rates. The Nernst equation represents the changes in temperature that can affect the overall electrode potential.

Learn more about Nernst Equation.

• Pressure: For gaseous electrode reactions, increasing the pressure increases the concentration of the gaseous species, which alters the electrode potential accordingly.
• Surface Area of Electrode: A larger surface area provides more sites for redox reactions to occur, resulting in an increased electrode potential and a larger surface area of the electrodes also makes the transfer of electrons more efficient.
• pH and Concentration of Electrolyte: pH of the electrolyte solutions affects electrode potential, especially for those electrodes which involve hydrogen ions. Changing pH is nothing but a change in the concentration of hydrogen ions, and a change in concentration changes the rate of reaction.

Electrode Potential and Standard Electrode Potential are key concepts in the field of electrochemistry which is the branch of chemistry that deals with relationships between electric potential differences and observable chemical change. Electrode Potential is also used extensively in the development of sustainable battery technologies, as all modern-day batteries work on this principle to create voltage for the smooth operations of electronic gadgets. This article deals with the topic of Electrode Potential and Standard Electrode Potential in detail and helps us understand how electricity or potential is produced using chemistry.