Faraday's Second Law of Electrolysis describes the relationship between the quantities of different substances deposited at electrodes when the same amount of charge is passed through different electrolytic solutions.
Faraday's First Law states that the mass of a substance deposited is directly proportional to the charge passed. Faraday's Second Law compares different substances at the same charge.
"When the same quantity of electricity is passed through different electrolytes connected in series, the masses of substances deposited at the respective electrodes are directly proportional to their equivalent masses (chemical equivalents)."
Mathematically:
m₁/m₂ = E₁/E₂
Where:
The Equivalent Mass (or Chemical Equivalent) is calculated as:
Equivalent Mass = Molar Mass / Valency (n-factor)
Example: If you pass the same charge through aqueous CuSO₄ and AgNO₃:
For every 32 g of copper deposited, 108 g of silver will be deposited simultaneously.
It is used in **electroplating** industries to precisely calculate how much of a metal (like gold or silver) will be deposited on an object for a given amount of current and time.
What is a Polyatomic Ion? (Definition & Examples)
Learn the definition of a polyatomic ion in chemistry. Discover clear examples like Sulphate (SO4), Nitrate (NO3), and Ammonium (NH4) for Class 9 students.
What is the Degree of Dissociation?
Learn the definition and formula for the degree of dissociation (alpha). Understand its importance in weak acids, weak bases, and chemical equilibrium.
Density of Petrol — What Is the Density of Petrol (Gasoline)?
The density of petrol (gasoline) is approximately 0.71–0.77 g/mL (710–770 kg/m³). It is less dense than water, which is why petrol floats on water. Learn with FAQs.
What Is Desiccated Coconut? Drying Process and Chemistry Explained
Desiccated coconut is coconut flesh with moisture removed by drying at low temperatures. It preserves coconut by reducing water activity, inhibiting microbial growth. Used widely in food.
BOD and COD — Water Pollution Indicators
Learn the definition and difference between BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand). Essential environmental chemistry notes.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.