Electrochemistry Important Questions for Class 12 | JEE & NEET
Electrochemistry Important Questions: This section includes the most important and frequently asked electrochemistry questions for Class 12 board exams, JEE, and NEET. These questions are based on NCERT concepts, previous year trends, and high-scoring exam areas.
Electrochemistry is one of the most scoring yet conceptual chapters in Physical Chemistry. Every year, multiple questions are asked from this chapter in CBSE Boards, JEE Main, JEE Advanced, and NEET. Practicing important questions helps students understand electrode potential, EMF, electrolysis, and Faraday’s laws in depth.
Very Short Answer Questions (1 Mark)
- Define electrochemistry.
- What is an electrochemical cell?
- What is standard electrode potential?
- State Faraday’s first law of electrolysis.
- What is EMF of a cell?
Answers:
- Electrochemistry deals with the relationship between chemical reactions and electrical energy.
- An electrochemical cell converts chemical energy into electrical energy.
- Standard electrode potential is the potential of an electrode measured under standard conditions.
- Faraday’s first law states that the mass deposited is proportional to the charge passed.
- EMF is the maximum potential difference between two electrodes of a cell.
Short Answer Questions (2–3 Marks)
- Write the relation between Gibbs free energy change and EMF of a cell.
- Why is the conductivity of an electrolyte lower than that of a metal?
- What is the role of salt bridge in an electrochemical cell?
Sample Answer:
Role of Salt Bridge: A salt bridge maintains electrical neutrality by allowing the flow of ions between the two half cells and completes the circuit without mixing the solutions directly.
Exam Tip: Questions on salt bridge are frequently asked in both CBSE and NEET exams.
Long Answer Questions (5 Marks)
- Derive the Nernst equation for a single electrode potential.
- Explain electrolysis with the help of Faraday’s laws.
- Describe construction and working of a Daniell cell with diagram.
Important Point:
Derivations from electrochemistry are very important for board exams and are often directly asked. Students must write proper equations and units to score full marks.
Important Numerical-Based Questions
- Calculate the EMF of a cell if E°(Zn²⁺/Zn) = –0.76 V and E°(Cu²⁺/Cu) = +0.34 V.
- How much silver is deposited when 9650 C of charge is passed?
Answer (Example):
EMF = E°cathode – E°anode
EMF = 0.34 – (–0.76) = 1.10 V
MCQs – Electrochemistry (JEE & NEET)
Q1. Which of the following has the highest standard reduction potential?
A. Zn²⁺/Zn
B. Cu²⁺/Cu
C. Fe²⁺/Fe
D. Mg²⁺/Mg
Correct Answer: B
Explanation: Copper has the highest positive reduction potential, hence greater tendency to get reduced.
Frequently Asked Questions (FAQs)
Is electrochemistry important for NEET?
Yes, electrochemistry is one of the most important chapters for NEET, with 2–3 direct questions every year.
Which part of electrochemistry is most important?
Electrode potential, Nernst equation, Faraday’s laws, and numericals are the most important areas.
Is electrochemistry scoring?
Yes, with proper practice of numericals and concepts, electrochemistry is highly scoring.
NCERT & Exam Relevance
- Based strictly on NCERT Class 12 syllabus
- Important for CBSE Boards, JEE Main, JEE Advanced & NEET
- Repeated questions from previous year exams
NCERT Class 12 Chemistry Textbook
Electrochemistry Numericals with Solutions
CHEMASH – Simplifying Chemistry for Class 11, 12, JEE & NEET Aspirants
