Quick answer: A galvanic cell converts the energy of a spontaneous redox reaction into electrical energy. Oxidation occurs at the anode, reduction occurs at the cathode and electrons flow through the external circuit. The Nernst equation calculates cell potential under non-standard conditions, while ΔG = −nFE connects cell potential with Gibbs energy and spontaneity.
What you will learn
- Construction and working of a galvanic cell
- Daniell cell, anode, cathode and salt bridge
- Standard electrode and cell potentials
- Relationship between Ecell and Gibbs free energy
- Nernst equation and numerical applications
Video chapters
- 0:00 Introduction to Electrochemistry
- 2:18 What is an Electrochemical Cell?
- 4:51 Electrochemical vs Electrolytic Cells
- 9:55 Daniell Cell Construction and Working
- 12:40 Standard Electrode Potential
- 16:36 Oxidation and Reduction
- 20:42 Salt Bridge
- 31:29 Cell Potential and Gibbs Free Energy
- 42:15 Nernst Equation
- 50:26 Nernst Equation Numericals
- 59:52 Lesson Recap
Important questions answered
What is a galvanic cell?
It is an electrochemical cell that produces electrical energy from a spontaneous oxidation–reduction reaction.
What is the function of a salt bridge?
It completes the internal circuit, maintains electrical neutrality and limits direct mixing of the two electrolytes.
How are Gibbs energy and cell potential related?
They are related by ΔG = −nFE. A positive cell potential gives a negative ΔG for a spontaneous cell reaction.
What does the Nernst equation calculate?
It calculates electrode or cell potential when concentration, pressure or other reaction conditions are not standard.
Who should use this lesson?
This lesson is useful for school students, competitive-exam aspirants, parents supporting a learner and teachers looking for a clear explanation. Watch the complete video, make short notes and then practise the ideas without looking at the solution.
Learn with Lalit Kumar Mishra
Lalit Kumar Mishra is a chemistry educator, student success mentor, author and Founder of Topper Formula, with more than 20 years of teaching experience. Explore more learning and mentoring resources on the Resources page.