chemistry (Class 12) — Free Notes (CBSE & HBSE)
Free Class 12 Chemistry notes — NCERT solutions, sample papers 2026, previous year question papers (PYQs), chapter-wise revision and important MCQs. Solid State, Electrochemistry, Organic, Polymers and more. CBSE/HBSE + JEE Main + NEET.
Free, chapter-wise chemistry notes for Class 12 on Siksha Sarovar, aligned to NCERT and both CBSE and Haryana Board (HBSE). Covers 16 chapters with explanations, worked examples and board-pattern practice questions.
Chapters covered (16)
- The Solid State — Classification of solids into crystalline and amorphous, crystal lattice and unit cells, packing efficiency, density calculations, and crystal defects in Class 12 Chemistry.
- Solutions — Types of solutions, concentration expressions (molarity, molality, mole fraction), Raoult's law, Henry's law, colligative properties (boiling point elevation, freezing point…
- Electrochemistry — Electrochemical cells, Galvanic and electrolytic cells, standard electrode potential, Nernst equation, conductance, Kohlrausch's law, Faraday's laws, and batteries.
- Chemical Kinetics — Rate of reaction, rate law, order and molecularity, integrated rate equations, half-life, temperature dependence, Arrhenius equation, activation energy and collision theory.
- Surface Chemistry — Adsorption (physisorption vs chemisorption), adsorption isotherms, catalysis (homogeneous and heterogeneous), enzyme catalysis, colloids (preparation, properties, coagulation) and…
- Isolation of Elements — General principles of metallurgy: concentration of ores (froth flotation, leaching), thermodynamic principles of extraction (Ellingham diagram), electrochemical reduction, and…
- p-Block Elements (Groups 15-18) — Group 15 (N, P): allotropes, compounds. Group 16 (O, S): allotropes, H2SO4. Group 17 halogens and Group 18 noble gases, interhalogen compounds.
- d- and f-Block Elements — Transition elements: electronic configuration, properties (variable oxidation states, colored compounds, magnetic behavior, catalytic activity), important compounds KMnO4 and…
- Coordination Compounds — Werner's theory, IUPAC nomenclature, isomerism (structural and stereoisomerism), valence bond theory (VBT), crystal field theory (CFT) and effective atomic number (EAN).
- Haloalkanes and Haloarenes — Classification, preparation of haloalkanes and haloarenes, nucleophilic substitution (SN1 and SN2), elimination reactions, stereochemistry, and polyhalogen compounds (DDT, BHC,…
- Alcohols, Phenols and Ethers — Preparation and reactions of alcohols and phenols, acidity comparison, reactions of phenol (electrophilic substitution), Williamson synthesis of ethers, industrial importance.
- Aldehydes, Ketones and Carboxylic Acids — Preparation of aldehydes and ketones, nucleophilic addition reactions (aldol, Cannizzaro, Clemmensen), carboxylic acid preparation and reactions (esterification,…
- Amines — Classification and nomenclature of amines, preparation (nitro reduction, Hoffmann's degradation), basicity (alkyl vs aryl), diazotization, Sandmeyer and coupling reactions.
- Biomolecules — Carbohydrates (classification, glucose structure, reducing/non-reducing sugars), proteins (amino acids, peptide bond, protein structure levels), nucleic acids (DNA/RNA), vitamins…
- Polymers — Classification of polymers, addition and condensation polymerization, natural and synthetic rubbers, biodegradable and non-biodegradable polymers.
- Chemistry in Everyday Life — Drugs and medicines classification, drug-target interaction, chemicals in food (preservatives, sweeteners, antioxidants), and soaps and detergents.
The Solid State: Classification and Types of Solids
The Solid State
Classification of Solids
Solids are substances with definite shape and volume due to strong intermolecular forces. Based on the arrangement of constituent particles, solids are classified as crystalline or amorphous.
Crystalline Solids: Have a regular, repeating three-dimensional arrangement of particles (crystal lattice). They are true solids with sharp melting points, anisotropy, and clean cleavage. Examples: NaCl, KCl, diamond, quartz, metals.
Amorphous Solids: Lack long-range order. Called pseudo-solids or super-cooled liquids. Isotropic, no sharp melting point. Examples: Glass, rubber, plastics, wax.
Types of Crystalline Solids
| Type | Particles | Binding Forces | Melting Point | Conductivity | Examples |
|---|---|---|---|---|---|
| Ionic | Cations + Anions | Electrostatic | High (600-3000 C) | Poor (solid), Good (melt) | NaCl, MgO, CaCl2 |
| Covalent | Atoms | Covalent bonds | Very high | Poor (except graphite) | Diamond, SiO2, SiC |
| Molecular | Molecules | Van der Waals, H-bonds | Low | Poor | Ice, CO2, glucose |
| Metallic | Metal ions + e- sea | Metallic bond | Variable | Good | Cu, Fe, Na, Mg |
Special Cases
Graphite: Covalent solid conducting electricity due to delocalized pi electrons between sp2 carbon layers. Soft due to weak Van der Waals between layers. Ice: Molecular solid with high mp (0 C) relative to other molecular solids due to extensive H-bonding (O-H...O).
Anisotropy vs Isotropy
Anisotropy in crystalline solids: different properties in different directions (different arrangement of particles). Isotropy in amorphous solids: same properties in all directions (random arrangement).
Bragg's Law
X-ray diffraction determines crystal structure. nλ = 2d sinθ where n = order, λ = wavelength, d = interplanar spacing, θ = angle.
Frequently asked questions
Are these chemistry notes free?
Yes — all chemistry notes on Siksha Sarovar are free to read, no account required.
Do the notes follow CBSE and HBSE?
Yes. Notes are NCERT-aligned and include both CBSE and Haryana Board (HBSE) exam guidance, important questions and MCQs.
Can I prepare for board exams here?
Yes — each chapter includes key concepts, formulas, important questions and practice MCQs for board exam revision.