Key Chapters for Chemistry Numericals in CBSE Class 12
In the CBSE Class 12 Chemistry curriculum, numerical problems are widely asked from certain chapters. These problems are crucial for understanding and applying concepts in real-world scenarios. Below is a comprehensive breakdown of the chapters where such numericals are commonly found, along with examples of the types of problems you might encounter.
Chapters Known for High Probability of Numericals
The following chapters are particularly well-known for their extensive use of numerical problems. Regular practice in these areas will significantly improve your preparation for the exam.
1. Class 1: The Solid State
Chapter 1 on The Solid State often includes numericals involving calculations related to unit cell dimensions, packing efficiency, density, and crystal defects. Students should be familiar with the following concepts:
Calculations related to unit cell dimensions Packing efficiency calculations Density of crystal structures Crystal defects and their calculations2. Class 2: Solutions
Chapter 2 on Solutions is another chapter with a high probability of numericals. Expected problems include calculations on concentration terms, colligative properties, and dilution. Topics to focus on include:
Molarity, molality, and normality calculations Colligative properties like boiling point elevation and freezing point depression Osmotic pressure calculations Dilution calculations3. Class 3: Electrochemistry
Chapter 3 on Electrochemistry frequently tests redox reactions and related calculations involving stoichiometry, molar conductivity, emf, and electrochemical cells. Key areas include:
Redox reaction calculations Molar conductivity calculations Electrode potential and emf calculations Electrochemical cell calculations4. Class 4: Chemical Kinetics
Chapter 4 on Chemical Kinetics covers rate laws, rate constants, order of reactions, and half-life calculations. Important topics include:
Rate law and rate constant calculations Order of reactions and how to determine it Half-life calculations Arrhenius equation applications5. Class 5: Surface Chemistry
Chapter 5 on Surface Chemistry often includes numerical problems involving adsorption isotherms, efficiency of adsorbents, and catalysis. Key areas are:
Adsorption isotherm calculations Efficiency of adsorbents Catalysis and related calculations6. Class 9: Coordination Compounds
Chapter 9 on Coordination Compounds frequently involves numerical problems related to formulas, structures, isomerism, and stability determination. Important topics include:
Formulas and structures of coordination compounds Isomerism and its determination Stability of coordination compounds7. Class 12: Haloalkanes and Haloarenes
Chapter 12 on Haloalkanes and Haloarenes can test reactions, mechanisms, and calculations related to yields, conversions, and rates. Topics include:
Reaction mechanisms Yield and conversion calculations Rate of reactionsModerate Probability of Numericals
The following chapters have a moderate probability of numerical problems. Regular practice in these areas is still beneficial:
Chapter 13: Amines - Calculations related to basicity, preparation, and reactions Chapter 14: Biomolecules - Numerical problems on structures, identification tests, and conversionsLow Probability of Numericals
The chapter on Chemistry in Everyday Life (Chapter 16) focuses more on qualitative understanding and applications and rarely includes numerical problems. However, it is still essential to understand the core concepts thoroughly.
Conclusion: The actual weightage of numerical problems in each chapter can vary. However, by focusing on the core concepts and practicing a variety of problems, you can significantly enhance your preparation for the CBSE Class 12 Chemistry examination. Always refer to the syllabus and practice sample papers to get a clearer idea of the exam pattern and difficulty level.