The electrochemical series, also known as the activity series, is a list that describes the arrangement of elements in the order of their increasing electrode potential values. The series has been established by measuring the potential of various electrodes versus standard hydrogen electrodes (SHE) . In the electrochemical series, the electrodes (metals and non-metals) in contact with their ions are arranged on the basis of the values of their standard reduction or oxidation potentials. The most negative E° values are placed at the top of the electrochemical series, and the most positive at the bottom. The electrochemical series helps to identify a good oxidizing agent or reducing agent. All the substances appearing on the top of the electrochemical series are good oxidizing agents, i.e., they have a positive value of standard reduction potential, whereas those appearing on the bottom of the electrochemical series are good reducing agents, i.e., they have a negative value of standard reduction potential.

Some of the applications of the electrochemical series are:

• Oxidizing and Reducing Strengths: The electrochemical series helps to identify the substances that are good oxidizing agents and reducing agents. All the substances appearing on the top of the series behave as good reducing agents. All the substances appearing at the bottom of the table are good oxidizing agents.

• Displacement reactions: A metal higher in the series will displace the metal from its solution which is lower in the series. A metal higher in the series has a greater tendency to provide electrons to the cations of the metal to be precipitated. The metal having low standard reduction potential will displace the metal from its salts solution which has a higher value of standard reduction potential.

In summary, the electrochemical series is a list that describes the arrangement of elements in the order of their increasing electrode potential values. It helps to identify good oxidizing and reducing agents and is used in displacement reactions.