A Synopsis on Cell Potentials

The electromotive force of a cell made up of two electrodes is known as the electrode potential in electrochemistry.

The letter E stands for it. It is impossible to directly quantify the absolute value of a single electrode potential. Experimentally, only the difference in potential between two electrodes may be measured. So, in an experiment to measure electrode potential, one electrode is used as a reference electrode with a known potential, while another electrode with an unknown potential is used in a cell. The cell potential, which is equal to the total of the potentials on the two electrodes, is measured experimentally.

E_Anode + E_Cathode = E_Cell

The electrode potential of one electrode is already known, hence the electrode potential of another (electrode with unknown electrode potential) can be estimated using a voltmeter.

What does it mean to have a standard electrode potential?

The standard electrode potential for that half-cell or half-reaction is the potential of the half-reaction (half-cell) measured against the standard hydrogen electrode under standard conditions. Standard conditions are a temperature of 298K, a pressure of 1 atm, and an electrolyte concentration of 1M. It is calculated using typical hydrogen electrodes.

A gas – ion electrode is the most common type of hydrogen electrode. It is used to determine the standard electrode potential of elements and other half cells as a reference electrode. It may function as both an anode and a cathode half-cell. At 25°C or 298K, its standard reduction potential and standard oxidation potential are both zero. It is the foundation of the oxidation-reduction potentials thermodynamic scale.

E0 stands for the standard electrode potential. A standard hydrogen electrode can be used to compute either a standard reduction potential or a standard oxidation potential for an electrode. The difference between the standard reduction potentials of two half–cells or half–reactions is the standard cell potential. – is one way to express it.

E_Cathode – E_Anode = E_Cell

Series of electrochemical reactions

Electrochemical series refers to the arrangement of components based on their standard electrode potential values. It’s also known as an activity sequence. Higher standard electrode potential elements are placed over lower standard electrode potential elements. The items at the very top of the series have a tendency to be easily decreased. The elements near the bottom, on the other hand, have the least inclination to be decreased.

Fluorine has the highest standard electrode potential, hence it has the greatest inclination to be decreased. Because lithium has the lowest standard electrode potential, it has the least tendency to be lowered. As a result, fluorine is a strong oxidizing agent, while lithium is a strong reducing agent.

Standard Electrode Potentials and Their Applications

The following are some of the applications of standard electrode potentials:

• It’s a tool for determining the relative strengths of various oxidants and reductants.
• It’s used to figure out how to determine standard cell potential.
• It’s used to foresee possible outcomes.
• Prediction of the reaction’s equilibrium.

Significance of Standard Electrode Potential

• Redox reactions take place in an electrochemical cell, which is made up of two half-reactions.
• Oxidation occurs at the anode end, whereas reduction occurs at the cathode end. At the anode end, oxidations result in electron loss, while at the cathode end, electron gain occurs. Electrons go from anode to cathode, causing electricity to flow.
• The difference in potentials between the cathode and anode of each electrode dipped in its electrolyte causes electric potential. A voltmeter is used to determine the cell potential.

• It is impossible to obtain the potentials of individual half-cells. Because the individual potential may fluctuate with a change in pressure, temperature, or electrolyte content, the true relevance of Standard Electric Potential emerges. A Standard Hydrogen Electrode is used to assess the individual reduction potential of a half-cell (SHE). SHE has a 0 volt electrode potential.

• The standard electrode potential of an electrode can be estimated by attaching an electrode to the SHE and measuring the cell potential of the resulting galvanic cell. The oxidation potential of an electrode is the inverse of its reduction potential. As a result, the standard electrode potential of an electrode is defined by the standard reduction potential.

• Good oxidising agents have high standard reduction potentials, while good reducing agents have low standard reduction potentials.

• Redox reactions take place in an electrochemical cell, which is made up of two half-reactions.

• Oxidation occurs at the anode end, whereas reduction occurs at the cathode end. At the anode end, oxidations result in electron loss, while at the cathode end, electron gain occurs. Electrons go from anode to cathode, causing electricity to flow.

• The difference in potentials between the cathode and anode of each electrode dipped in its electrolyte causes electric potential. A voltmeter is used to determine the cell potential.

• It is impossible to obtain the potentials of individual half-cells. Because the individual potential may fluctuate with a change in pressure, temperature, or electrolyte content, the true relevance of Standard Electric Potential emerges. A Standard Hydrogen Electrode is used to assess the individual reduction potential of a half-cell (SHE). SHE has a 0 volt electrode potential.

• The standard electrode potential of an electrode can be estimated by attaching an electrode to the SHE and measuring the cell potential of the resulting galvanic cell. The oxidation potential of an electrode is the inverse of its reduction potential. As a result, the standard electrode potential of an electrode is defined by the standard reduction potential.

• Good oxidizing agents have high standard reduction potentials, while good reducing agents have low standard reduction potentials.

• Redox reactions take place in an electrochemical cell, which is made up of two half-reactions.

• Oxidation occurs at the anode end, whereas reduction occurs at the cathode end. At the anode end, oxidations result in electron loss, while at the cathode end, electron gain occurs. Electrons go from anode to cathode, causing electricity to flow.

• The difference in potentials between the cathode and anode of each electrode dipped in its electrolyte causes electric potential. A voltmeter is used to determine the cell potential.

• It is impossible to obtain the potentials of individual half-cells. Because the individual potential may fluctuate with a change in pressure, temperature, or electrolyte content, the true relevance of Standard Electric Potential emerges. A Standard Hydrogen Electrode is used to assess the individual reduction potential of a half-cell (SHE). SHE has a 0 volt electrode potential.

• The standard electrode potential of an electrode can be estimated by attaching an electrode to the SHE and measuring the cell potential of the resulting galvanic cell. The oxidation potential of an electrode is the inverse of its reduction potential. As a result, the standard electrode potential of an electrode is defined by the standard reduction potential.

• Good oxidizing agents have high standard reduction potentials, while good reducing agents have low standard reduction potentials.

Conclusion

Only aqueous equilibrium can be measured using standard electrode potentials. Using typical electrode potentials, we can estimate reaction possibilities, but not the rate of reaction.

This was a quick overview of standard electrode potential and how to calculate it using examples. Concentrate on the notion and how it is calculated.