Faraday Constant Overview
The Faraday constant is the quantity or magnitude of electric charge carried by one mole of electrons. It is indicated by the letter F and was named after Michael Faraday. Coulombs per mole (C/mol) is the unit of measurement for the constant. The Faraday constant is frequently used in electrolysis calculations.
What is the Faraday Constant?
The Faraday constant, indicated by the letter F and commonly written as F in physical chemistry, is the electric charge per mole of elementary charges. It bears the name of the English physicist Michael Faraday. The Faraday constant has had the precisely defined value given by the product of the elementary charge e and the Avogadro constant NA since the 2019 redefinition of SI base units, which took effect on May 20, 2019.
Faraday Constant Highlights
The following table gives details about what faraday constant is-
|
Particulars |
Details |
|
Definition |
One mole of basic charges' electric charge. |
|
Symbol |
F |
|
Value |
9.648 x 10⁴ C.mol⁻¹ |
Who was Michael Faraday?
Michael Faraday (22 September 1791–25 August 1867) was an English scientist who contributed significantly to the fields of electromagnetics and electrochemistry. He was born in London and died there. Among his most notable discoveries are the concepts underpinning electromagnetic induction, diamagnetism, and electrolysis.
Read more about the Magnetic Effects of Electric Current and Eddy Current.
Faraday Constant Formula
This constant may be represented using two additional physical constants as follows-
F = e x N🇦
e is the electron's charge in coulombs-
e = 1.602 176 634 x 10⁻¹⁹ C
NA is the Avogadro constant.
NA = 6.022141 × 1023 mol⁻¹.
= 1.602 176 634 x 10⁻¹⁹ C x 6.022 140 76 x 10²³ mol⁻¹
= 9.648 533 212 331 001 84 x 10⁴ C.mol⁻¹
Faraday Constant Derivation
The Faraday constant is useful in electrochemistry because it is a conversion factor between the mole (used in chemistry) and the coulomb (used in physics and practical electrical measurements). Because one mole contains precisely 6.022 140 76 x 10²³ entities, and 1 coulomb is made up of precisely 1/e = 10¹⁹/1.602 176 634 elementary charges, the quotient of these two values yields the Faraday constant-
F = N🇦/1/e = 9.648 533 212 331 001 84 x 10⁴ C.mol⁻¹
The Faraday constant is frequently used in electrolysis calculations. To calculate the chemical quantity of an electrolyzed material (in moles), divide the amount of charge (the current integrated over time) by the Faraday constant. To begin, the value of F was calculated by measuring the quantity of silver deposited in an electrochemical reaction in which a measured current was transmitted for a measured period and applying Faraday's law of electrolysis.
Faraday Constant- A Unit of Charge
The "Faraday," a unit of electrical charge, is related to the Faraday constant. It is significantly less frequent than the coulomb; however, it is employed in electrochemistry on occasion. One faraday of charge is the magnitude of one mole of electron charge, i.e..,
1 Faraday = Faraday x 1 mol 9.648 533 212… x 10⁴ C
The Faraday constant F, on the other hand, equals one Faraday per mole. The faraday should not be confused with the farad, which is an unrelated capacitance unit (1 farad = 1 coulomb / 1 volt).
Other Common Units of Faraday Constant
The following are other common units of the Faraday constant-
- 96.485 kJ per volt–gram-equivalent
- 23.061 kcal per volt–gram-equivalent
- 26.801 A·h/mol
Faraday Constant Calculation
Electrolysis is one of the most popular applications of the Faraday constant. The number of oxidized elements may be calculated by dividing the amount of charge in coulombs by the Faraday constant.
Read more about the Working Principle of Transformer.
How Does the Faraday Constant Work?
The following are some of the details of an electrolytic cell to see how Faraday's constant works-
- An electrolytic cell is made up of two electrodes immersed in an electrolyte solution.
- When an electric current is applied to the electrodes, one operates as an anode and the other as a cathode.
- Oxidation occurs at the anode, and the anode loses electrons.
- Reduction occurs at the cathode, and the cathode acquires electrons.
- Electrons lost at the anode are transferred to the cathode through the external circuit.
- The quantity of electric charge that passes through the cell is proportional to the amount of material oxidized or reduced at the electrodes.
The figure below depicts this procedure-
Faraday Constant vs. Faraday Unit
The Faraday unit of electrical charge represents the magnitude of the charge in each mole of electrons. As a result, the Faraday constant may be expressed as a lowercase f, which is equivalent to only one Faraday. Please keep in mind that the Faraday constant should not be confused with the farad, which is expressed as 1 farad = 1 coulomb per volt. This is a capacitance unit that was named after the English physicist Michael Faraday.
Faraday Constant Applications
The Faraday constant is used in a multitude of domains, including electrochemistry, thermodynamics, battery technology, analytical chemistry, and others. The following are some of the applications of the Faraday constant-
Analytical Chemistry
Faraday's constant is used in many different techniques in analytical chemistry, such as voltammetry, to quantify the quantity of material involved in an electrochemical process. This equation may then be used to identify and quantify the concentration of various species in solutions.
Battery Technology
Faraday's constant is critical in determining the capacity of a battery. The constant is used to calculate the amount of charge necessary to make one mole of a chemical, which is important in estimating the amount of energy stored in a battery.
Electrochemical Cells
In the theoretical study of electrochemical cells, we use Faraday's constant to compute the potential difference between the electrodes and the quantity of material engaged in the redox processes.
Read more about the Electrochemical Series and EMF Equation of Dc Generator.
Electrochemistry
In electrochemistry, we use Faraday's constant to compute the amount of electric charge involved in a chemical process, as well as the electrochemical equivalent of a material. This constant is used to calculate the connection between the amount of electric charge passing through an electrolytic cell and the amount of material electrodeposited or dissolved at the electrodes.
Thermodynamics
Faraday's constant is used in thermodynamics to compute the Gibbs free energy of electrochemical processes, which is useful in understanding the thermodynamics of electrochemical systems.
Points to Remember
The Faraday constant is the amount of charge carried by one mole of electrons.
F = eNA is the formula for calculating Faraday's constant.
The internationally recognized value is F = 96485.33289 C/mol.
A faraday equals one coulomb.
A Faraday is also a capacitance unit.
This Faraday constant is commonly employed in electrolysis and may be used to compute the moles of oxidized elements.
Conclusion
The charge carried by one mole of electrons is essentially Faraday's constant. Although it is less often used, it is primarily employed in the field of electrochemistry. This is a conversion factor between moles and coulombs.