April 06, 2025
Faraday's Law: The Foundation of Electrochemical Reactions
The application of electrochemistry has its critical importance in various scientific processes, especially during battery operations and electroplating practices, and metal refining stages. Michael Faraday introduced in 1834 the essential electrochemical principle known as Faraday’s Law of Electrolysis. These laws establish a direct quantitative connection between the electric charge flowing through electrolytes to the quantity of substances that form or are released at either electrode.
To excel in NEET exams, Faraday’s Laws must be learned thoroughly by students since they serve as the basis for solving electrochemistry-based numerical problems while helping students understand the operations of electrolytic cell batteries and the industrial applications of electrolysis. The following article describes Faraday's Laws, including their mathematical formulas together with their practical uses, while examining their importance in electrochemistry.
Define Faraday’s Laws of Electrolysis
First Law of Electrolysis
Statement: The quantity of electricity (electric charge) that moves through an electrolytic solution is directly related to the mass of substances deposited or liberated at the electrodes.
Mathematically, Faraday’s law equation is:
m=ZQ
where:
- m = mass of the substance deposited at the electrodes (grams)
- Z = electrochemical equivalent of the substance (g/C)
- Q = total charge passed (Coulombs)
Since Q = It (where I = current in amperes, t = time in seconds), we can also write:
m = ZIt
This means that increasing the current or duration of electrolysis will result in more material being deposited at the electrode.
Second Law of Electrolysis
Statement: The masses of different substances deposited or liberated by the same quantity of electricity are proportional to their chemical equivalent weights.
Mathematically, the Faraday formula is:
m1/m2=E1/E2
where:
- m₁, m₂ = masses of substances deposited
- E₁, E₂ = equivalent weights of substances
This law explains why different elements deposit at different rates under the same electrochemical conditions.
Applications of Faraday’s Laws
1. Electroplating
- Used to coat objects with a thin layer of metal, like gold, silver, or nickel.
- Helps in corrosion prevention and enhancing appearance.
2. Battery and Fuel Cells
- Used to determine battery capacity and efficiency.
- Helps in designing energy storage systems.
3. Purification of Metals (Electrorefining)
- Used for refining metals like copper, aluminum, and zinc.
Essential in the mining and electronics industries.
4. Industrial Electrolysis
- Used in hydrogen production, chlorine production, and sodium hydroxide production.
Numerical Example
Problem:
A current of 3A is passed through a CuSO₄ solution for 40 minutes. Find the mass of copper (Cu) deposited at the electrode. (Electrochemical equivalent of Cu = 0.000329 g/C).
Solution:
- Charge passed:
Q=I×t=3A×(40×60)s
Q=3×2400=7200C
- Mass deposited:
m=ZQ
=0.000329×7200
m = 2.37 gm = 2.37 g
Thus, 2.37 grams of copper will be deposited at the electrode.
Now let’s have a look at one of the most common types of questions from Faraday's law of electrochemistry for your NEET 2025.
Conclusion
The mathematical foundation needed to understand electrochemical reactions comes from Faraday’s Laws of Electrolysis. The laws enable making predictions about the amount of substance deposited or liberated during electrolysis reactions, which is vital in battery technology, electroplating, and industrial electrochemistry. Understanding Faraday's Laws is necessary to analyze both energy storage systems and metal refining operations. Learning Faraday’s Laws in chemistry becomes essential for NEET aspirants since they need these laws to tackle numerical problems connected to electrochemistry's real-world practical applications.
Frequently Asked Questions (FAQs)
1. What role does Faraday's Law play in electrochemistry?
Faraday's Laws define a direct quantitative relationship between electric charge and the amount of substance deposited in electrolytic processes. The laws play a crucial role in multiple industrial processes, including electroplating, metal refining applications, and battery technology development.
2. What are the steps to perform electroplating operations based on Faraday's Laws?
The electroplating process requires passing an electric current through metal salt solutions to form thin layers of metal on objects. The thickness of the plating depends on Faraday's First Law because this law establishes a direct relationship between electric charge flow and the amount of deposited metal.
3. Do Faraday's Laws have practical applications during battery development?
Through Faraday’s Laws, we determine battery efficiency and capacity since the electrical charge directly correlates to the chemical transformation. The design of effective rechargeable batteries for electric vehicles and energy storage systems heavily depends on this essential principle.
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