NCERT Solutions
Class 12 Chemistry
14 chapters · 25 important questions
The Solid State
Covers types of solids, crystal systems, packing in solids, and defects in crystals. Unit cell calculations and packing efficiency are common numericals.
Key Topics
Important Questions
Calculate the packing efficiency of a face-centred cubic unit cell.
What are Frenkel and Schottky defects? In which type of ionic solids does each occur?
Solutions
Covers types of solutions, Raoult's law, colligative properties, and van't Hoff factor. Abnormal molecular masses and determination of molecular masses are key.
Key Topics
Important Questions
What is osmosis? Derive the expression for osmotic pressure. How is it used to determine molecular mass?
18g of glucose (C₆H₁₂O₆) is dissolved in 1kg of water. Calculate the freezing point depression (Kf = 1.86 K kg/mol).
Electrochemistry
Covers electrochemical cells, standard electrode potentials, Nernst equation, conductance, and batteries. Corrosion is also included.
Key Topics
Important Questions
Define conductivity and molar conductivity. How does molar conductivity vary with concentration for strong and weak electrolytes?
Chemical Kinetics
Covers rate of reaction, factors affecting rate, rate law, order of reaction, and Arrhenius equation. Integrated rate equations and half-life are key numericals.
Key Topics
Important Questions
What is the difference between order and molecularity of a reaction? Derive the integrated rate equation for a first order reaction.
Surface Chemistry
Covers adsorption, catalysis, colloids, and emulsions. Tyndall effect in colloids and Hardy-Schulze rule are important.
Key Topics
Important Questions
What is adsorption? Distinguish between physisorption and chemisorption.
What is the Tyndall effect? Give one example.
General Principles of Extraction of Elements
Covers principles and methods of extraction — concentration of ores, reduction, and refining. Ellingham diagram is an important concept.
Key Topics
Important Questions
What is the Ellingham diagram? How is it useful in the extraction of metals?
Describe the froth flotation method for concentration of sulphide ores.
The p-Block Elements
Covers Group 15 (N, P, As), Group 16 (O, S, Se), Group 17 (halogens), and Group 18 (noble gases). Preparation, properties and uses of important compounds are frequently asked.
Key Topics
Important Questions
Describe the industrial preparation of sulphuric acid by the Contact process.
Why does fluorine not show positive oxidation state unlike other halogens?
The d and f Block Elements
Covers transition elements and their general characteristics. Lanthanoids and actinoids are also included. Chemical reactions and oxidation states of Cr and Mn are important.
Key Topics
Important Questions
Explain why transition elements show variable oxidation states. Give examples.
What is lanthanoid contraction? What are its consequences?
Coordination Compounds
Covers nomenclature, Werner's theory, VBT, Crystal Field Theory, isomerism, and stability of coordination compounds. IUPAC naming rules are consistently asked.
Key Topics
Important Questions
Write the IUPAC name and draw the structure of [Co(NH₃)₄Cl₂]Cl.
Using VBT, explain the hybridisation and geometry of [Ni(CN)₄]²⁻.
Haloalkanes and Haloarenes
Covers nomenclature, preparation, properties and reactions. SN1 vs SN2 mechanisms, optical isomerism, and Grignard reagents are key topics.
Key Topics
Important Questions
Explain SN1 and SN2 reactions with examples. What factors favour each?
Alcohols, Phenols and Ethers
Covers nomenclature, preparation, and properties. Acidity of phenols and Lucas test for alcohols are frequently asked. Industrial preparation of ethanol and phenol are important.
Key Topics
Important Questions
Why is phenol more acidic than ethanol? Explain in terms of structure.
How is ethanol prepared industrially?
Aldehydes, Ketones and Carboxylic Acids
Covers nomenclature, preparation, and reactions of aldehydes, ketones, and carboxylic acids. Aldol condensation, Cannizzaro reaction, and Hell-Volhard-Zelinsky reaction are key.
Key Topics
Important Questions
Write the mechanism of aldol condensation.
Explain why aldehydes are more reactive than ketones in nucleophilic addition reactions.
Amines
Covers nomenclature, preparation, basicity, and reactions of amines. Diazonium salts and their synthetic importance are included. Comparison of basicity of primary, secondary, tertiary amines is a common question.
Key Topics
Important Questions
Arrange in order of basicity: primary, secondary, tertiary amine (in water). Justify.
How are diazonium salts prepared? Give two uses in synthesis.
Biomolecules
Covers carbohydrates, proteins, enzymes, vitamins, nucleic acids, and hormones. Classification of carbohydrates and protein structure levels are common board questions.
Key Topics
Important Questions
What are reducing sugars? Is sucrose a reducing sugar? Why?
Describe the four levels of protein structure.