Chemistry class 12th Electrolytic_Cells_and_Electrolysis

Electrolytic Cells and Electrolysis


### Introduction to Electrolytic Cells
An electrolytic cell is an electrochemical cell that drives a non-spontaneous redox reaction using
electrical energy.
Unlike galvanic cells, which generate electricity from spontaneous reactions, electrolytic cells require
an external
power source.


### Working Principle of Electrolytic Cells
Electrolytic cells operate based on the movement of ions in an electrolyte solution. A direct current
(DC)
power source is connected to two electrodes (anode and cathode) immersed in the electrolyte.


- **Anode (Positive Electrode):** Oxidation occurs here.
- **Cathode (Negative Electrode):** Reduction occurs here.


### Electrolysis Process
Electrolysis is the process of using an electric current to drive a non-spontaneous chemical reaction.
It involves:
1. Passing an electric current through an electrolyte.
2. Ions migrating to electrodes where oxidation and reduction occur.
3. The desired chemical reaction takes place.


### Electrochemical Reactions in Electrolysis
The reactions in an electrolytic cell depend on the electrolyte and electrode materials.
For example, in the electrolysis of molten sodium chloride:


- At the **cathode:** Na+ + e- -> Na (Reduction)
- At the **anode:** 2Cl- -> Cl2 + 2e- (Oxidation)


### Applications of Electrolysis
Electrolysis has numerous industrial applications, including:
- **Extraction of metals** (e.g., aluminum from bauxite).
- **Electroplating** (coating metals with a thin layer of another metal).
- **Production of chemicals** (e.g., hydrogen and oxygen from water electrolysis).
- **Purification of metals** (e.g., refining copper).