CBSE Class 12 Chemistry Important Questions 2026 - Most Expected for Board Exam
Exam Today: 28 February 2026
CBSE Class 12 Chemistry Board Exam 2026 is scheduled for today at 10:30 AM. These are the most expected questions based on previous year trends and CBSE sample papers.
Chapter-wise Weightage 2026
| Unit | Chapter | Marks | Importance |
|---|---|---|---|
| Unit I | Solutions | 7 | Very High |
| Unit II | Electrochemistry | 9 | Very High |
| Unit III | Chemical Kinetics | 7 | Very High |
| Unit IV | d and f Block Elements | 7 | High |
| Unit V | Coordination Compounds | 7 | Very High |
| Unit VI | Haloalkanes and Haloarenes | 6 | High |
| Unit VII | Alcohols, Phenols and Ethers | 6 | High |
| Unit VIII | Aldehydes, Ketones and Carboxylic Acids | 8 | Very High |
| Unit IX | Amines | 6 | High |
| Unit X | Biomolecules | 4 | Medium |
Most Expected Questions - Electrochemistry (9 Marks)
1. Define molar conductivity. How does it vary with concentration for strong and weak electrolytes? (3 marks)
Expected: 95% probability — asked in every alternate year
2. Calculate the emf of the cell: Zn | Zn2+ (0.1M) || Cu2+ (1M) | Cu. Given E°cell = 1.10V (3 marks)
Expected: Nernst equation numerical — comes every year
3. What is a fuel cell? Explain the working of H2-O2 fuel cell with diagram. (3 marks)
Expected: High probability
4. State Faraday laws of electrolysis. How many moles of electrons are required to deposit 10g of calcium? (3 marks)
Expected: Faraday law numericals — very high probability
Most Expected Questions - Chemical Kinetics (7 Marks)
1. Define order and molecularity of a reaction. Give one example each of zero order and first order reaction. (3 marks)
2. What is activation energy? Draw and explain the energy profile diagram for exothermic and endothermic reactions. (3 marks)
3. The rate constant for a first order reaction is 60 s-1. Calculate the time required to reduce the concentration to 1/16th of initial value. (2 marks)
Half-life numerical — appears almost every year
Most Expected Questions - Coordination Compounds (7 Marks)
1. What is crystal field theory? Explain how crystal field splitting occurs in octahedral complexes. (3 marks)
2. Name the following coordination compounds using IUPAC nomenclature: (i) [Co(NH3)6]Cl3 (ii) K2[PtCl4] (iii) [Cr(en)2Cl2]Cl (2 marks)
3. What is the difference between homoleptic and heteroleptic complexes? Give one example each. (2 marks)
Most Expected Questions - Aldehydes, Ketones and Carboxylic Acids (8 Marks)
1. How is benzaldehyde distinguished from acetophenone? Describe Tollens test and Fehling test. (3 marks)
2. Complete the following reactions and name the products: (i) Aldol condensation of acetaldehyde (ii) Cannizzaro reaction of formaldehyde (3 marks)
3. What is Hell-Volhard-Zelinsky reaction? Give the mechanism with one example. (2 marks)
Last Minute Revision Tips
Do This Right Now
- Revise all named reactions in Organic Chemistry
- Practice Nernst equation and Faraday law numericals
- Memorise IUPAC nomenclature rules for coordination compounds
- Revise half-life formulas for first order reactions
- Check distinction reactions (Tollens, Fehling, Lucas test)
Exam Day Tips
- Read all questions carefully before starting
- Attempt MCQs first — 16 marks secured quickly
- Show all steps in numericals for full marks
- Draw neat, labelled diagrams wherever asked
- Manage time: 3 mins per mark