Electrochemistry
Free NCERT-aligned study resource for the 2026–27 academic session.
CBSE weightage: 9 marks. This unit is part of the official 70-mark Chemistry theory course for 2026–27. citeturn0search11
1. What You Need to Learn
Electrochemical cells; galvanic cells; Nernst equation; conductance; electrolytic cells and electrolysis; batteries; fuel cells; corrosion.
2. Core Concepts & Formulae
Cell emf: E°cell = E°cathode − E°anode. Nernst equation at 298 K: E = E° − (0.0591/n) log Q. Conductance G = 1/R; conductivity κ = G(l/A); molar conductivity Λm = κ × 1000/C when C is in mol L⁻¹.
3. Common Mistakes
Always identify anode and cathode from the reaction, not from a memorised sign. In a galvanic cell oxidation occurs at the anode and reduction at the cathode. Check units carefully in conductivity and molar-conductivity problems.
4. Exam-Focused Practice
- Calculate Ecell from two standard electrode potentials.
- Use the Nernst equation for a non-standard concentration.
- Explain why molar conductivity increases on dilution and compare strong and weak electrolytes.
5. Quick Revision Checklist
- Can you define the key terms without looking at the book?
- Can you explain the main trend/reaction/mechanism with a reason?
- Can you solve a numerical or predict a product independently?
- Can you answer an application or competency-based question?