Electrochemistry

Introduction

• Subject: Understanding electrochemistry.
• Importance: One of the crucial parts of 12th-grade chemistry.
• Main Concept: Converting electric energy into chemical energy and vice versa.

Definition of Electrochemistry

• Definition 1: It is the branch of chemistry that deals with converting electric energy into chemical energy and chemical energy into electric energy.
• Definition 2: It studies the relationships between chemical reactions and the electric energy produced by them.

Main Elements

1. Electrolytic Cell

   • Definition: In this cell, chemical reactions are conducted using electric energy.
   • Example: Electrolysis of NaCl.
   • Main Events: Oxidation occurs at the anode and reduction occurs at the cathode.
   • Electrodes
     • Anode: Positive charge, oxidation occurs.
     • Cathode: Negative charge, reduction occurs.

2. Electrochemical Cell

   • Definition: In this cell, electric energy is produced using chemical energy.
   • Example: Daniel Cell (using zinc and copper).
   • Main Events: Electrons transfer from zinc to copper (oxidation at zinc and reduction at copper).
   • Electrodes
     • Anode: Negative charge, oxidation occurs.
     • Cathode: Positive charge, reduction occurs.

Process and Examples

1. Example of Electrolytic Cell

   • Circuit of NaCl: Connecting positive and negative electrodes (anode and cathode).
   • Process: Transfer of Na+ and Cl- ions and electrode reactions.

2. Example of Daniel Cell

   • System: Placing ZnSO4 and CuSO4 solutions in two separate containers.
   • Connection: Connecting Zinc and Copper strips with a galvanometer and switch.
   • Process: Electrons travel from zinc to copper and a reaction occurs.

Importance of Salt Bridge

• Definition: A conducting medium that connects two different cell compartments.
• Function: Balancing ions and completing the circuit.

Summary

• In electrochemistry, we learn about two main types of cells (electrolytic cell and electrochemical cell).
• Cells teach us how conversion occurs between different forms of energy.
• It is essential to understand the clear distinctions between both types of cells.

Important: In electrolytic cells, chemical reactions are conducted using electricity, whereas in electrochemical cells, electricity is produced from chemical reactions.

What's Next?

• In the next class, we will focus on a detailed study of electrochemical cells and related paper calculations.

Questions and Doubts: Comment below for any questions and doubts.