If you’ve heard of electrochemistry, you’ve likely heard of standard electrode potential and standard reduction potential. But what exactly is the difference between the two?
Explanation of standard electrode potential
Standard electrode potential (SEP) is a measure of the potential difference between a metal electrode and an electrolyte solution, while standard reduction potential (SRP) is a measure of the potential difference between an oxidized and reduced form of a species at the same temperature and pressure. SEP is usually expressed in volts, while SRP is usually expressed in millivolts.
SEP is used to determine the reduction potential of a given reaction, while SRP is used to determine the oxidation potential. Both are important for understanding how reactions take place in electrochemical cells.
Explanation of standard reduction potential
Standard reduction potential (also known as redox potential) is a measure of how easily a chemical species will reduce (gain electrons) in a redox reaction. Standard electrode potential (SEP) is a measure of the potential difference between two half-cells of an electrochemical cell when the cell is operating at standard state.
However, SEP is not the same as standard reduction potential, as it measures the potential difference between two half-cells, rather than the potential of one of the half-cells. In other words, SEP takes into account the effect of the other half-cell on the overall reaction, while standard reduction potential only considers the potential of the one species.
Comparison of standard electrode potential and standard reduction potential
The difference between standard electrode potential and standard reduction potential lies in the direction of electron flow. Standard electrode potential is the measure of the tendency for a chemical species (atom, ion, or molecule) to acquire electrons and form a negative ion when in contact with an electrical conductor. On the other hand, standard reduction potential is the measure of the tendency for a chemical species to gain electrons and form a negative ion when it is part of a redox reaction.
In other words, standard electrode potential is a measure of the ease of electron transfer when an electrical conductor is in contact with a chemical species, while standard reduction potential is a measure of the ease of electron transfer when a redox reaction occurs.
Applications of standard electrode potential and standard reduction potential
Standard electrode potential (SEP) and standard reduction potential (SRP) are two closely related and often confused terms. SEP is the measure of the potential difference between a metal and its ions in an electrolyte solution.
SRP, on the other hand, is the measure of the potential difference between a metal and its reduced form in an electrolyte solution. The main difference between these two is that SEP is the measure of the potential difference between a metal and its ions, whereas SRP is the measure of the potential difference between a metal and its reduced form. The applications of SEP and SRP are used to predict the direction of a reaction, the energy released or absorbed during a reaction, the strength of an electrolyte, and the feasibility of a cell.
SEP and SRP can also be used to determine the feasibility of a reaction, which can be calculated by the Nernst equation. This equation is used to calculate the difference in Gibbs free energy between reactants and products in a reaction. The Gibbs free energy is then used to determine the feasibility of the reaction.
Overall, SEP and SRP are important tools in predicting the direction, energy released or absorbed, strength of electrolyte, and feasibility of a reaction. By understanding the difference between SEP and SRP, chemists and engineers can gain a better understanding of chemical reactions and can better utilize these tools to predict the outcome of a reaction.
Further resources
Have you ever wondered what is the difference between standard electrode potential and standard reduction potential? To put it simply, standard electrode potential measures the potential of an electrode in an electrochemical cell when it is in its standard state, while standard reduction potential measures the potential of a species when it is reduced.
These two terms are essential for understanding electrochemistry and its various applications. Standard electrode potential is the measure of the electromotive force of the cell when all reagents are in their standard states, whereas standard reduction potential is the measure of the electromotive force of the cell when all reagents are in their reduced states. In other words, standard electrode potential measures the energy of the cell when all reactants are in their standard state, while standard reduction potential measures the energy of the cell when all reactants are in their reduced state.
Understanding the difference between these two terms can help you understand electrochemical processes and their various applications.
Bottom Line
In conclusion, the difference between standard electrode potential and standard reduction potential is that standard electrode potential is the potential difference between a standard hydrogen electrode and a given electrode, whereas standard reduction potential is the potential difference between a given half-reaction and a standard hydrogen half-reaction. Standard reduction potentials are used to calculate the equilibrium constant of a reaction, while standard electrode potentials are used to calculate the equilibrium potential of a reaction.
