Odisha 12th Board Chemistry Syllabus 2025-26: Download PDF Below

Unit

Topics

Unit I: Some Basic Concepts of Chemistry

• Importance & scope of chemistry • Nature of matter, laws of chemical combination • Dalton’s atomic theory: elements, atoms, molecules • Atomic/molecular masses, equivalent mass • Acid, base, salt, oxidants, reductants • Mole concept, molar mass, % composition • Empirical & molecular formula • Chemical reactions & stoichiometry (calculations)

Unit II: Structure of Atom

• Discovery of electron, proton, neutron • Atomic number, isotopes, isobars • Thomson’s, Rutherford’s & Bohr’s models (limitations) • Shells, subshells, orbitals • Dual nature, de Broglie’s relation, Heisenberg principle • Quantum numbers, shapes of s, p, d orbitals • Electron filling rules – Aufbau, Pauli, Hund • Electronic configuration, stability of half-filled shells

Unit III: Classification of Elements & Periodicity

• History & significance of classification • Modern periodic law, present periodic table • Periodic trends: atomic, ionic, inert gas radii; ionization enthalpy, electron gain enthalpy, electronegativity, valency, oxidation state • Nomenclature of elements with Z > 100

Unit IV: Chemical Bonding & Molecular Structure

• Valence electrons, ionic & covalent bonds • Bond parameters, Lewis structure, polarity • Covalent character of ionic bonds • VBT, resonance, VSEPR theory • Hybridization (s, p, d), molecular geometry • MOT of homonuclear diatomic molecules (qualitative) • Hydrogen bonding

Unit V: States of Matter – Gases & Liquids

• Three states, intermolecular forces, bonding, m.p. & b.p. • Gas laws: Boyle’s, Charles’, Gay Lussac’s, Avogadro’s law • Ideal gas equation, Avogadro’s number • Deviations from ideal behaviour, liquefaction, critical temperature • Kinetic theory – energy, molecular speeds (elementary) • Liquid state – vapour pressure, viscosity, surface tension

Unit VI: Chemical Thermodynamics

• System & surroundings; types of systems • Work, heat, energy; extensive & intensive properties • First law – internal energy, enthalpy, heat capacity, specific heat • ΔU & ΔH measurement, Hess’s law • Enthalpy changes (bond dissociation, combustion, formation, etc.) • Second law (intro), entropy, Gibbs free energy, spontaneity, equilibrium criteria • Third law (intro)

Unit VII: Equilibrium

• Physical & chemical equilibrium, dynamic nature • Law of mass action, equilibrium constants (Kc, Kp, Kx) & relationships • Le Chatelier’s principle (factors) • Ionic equilibrium – ionization of acids/bases, electrolytes, degree of ionization • pH concept, Henderson equation • Hydrolysis of salts, buffer solutions • Solubility product, common ion effect • Numerical problems

Unit VIII: Redox Reaction

• Oxidation & reduction concepts • Oxidation number • Balancing redox reactions (electron & oxidation number method) • Applications of redox reactions

Unit IX: Hydrogen

• Position in periodic table, occurrence, isotopes • Preparation, properties, uses of hydrogen • Hydrides: ionic, covalent, interstitial • Properties of water, heavy water • Hydrogen peroxide: preparation, reactions, structure, uses • Hydrogen as fuel

Unit X: s-Block Elements (Group 1 & 2)

• General intro, electronic configuration, occurrence • Anomalous behaviour of 1st element, diagonal relationship • Trends in properties (ionization enthalpy, radii, reactivity) • Important compounds: – Na₂CO₃, NaCl, NaOH, NaHCO₃, CaO, CaCO₃ • Biological importance: Na, K, Mg, Ca

Unit XI: Some p-Block Elements

Group 13 (Boron Family): • General intro, electronic config., occurrence, oxidation states, properties • Boron: properties, Borax, Boric acid, Boron hydrides • Aluminium: reactions with acids/alkalies, uses Group 14 (Carbon Family): • General intro, occurrence, oxidation states, properties • Carbon – catenation, allotropes, oxides • Important compounds of Si: SiCl₄, Silicones, Silicates, Zeolites

Unit XII: Organic Chemistry – Basic Principles & Techniques

• Purification methods • Qualitative & quantitative analysis • Classification & IUPAC nomenclature • Electronic effects: inductive, electromeric, resonance, hyperconjugation • Bond fission: homolytic, heterolytic • Reactive intermediates: free radicals, carbocations, carbanions • Electrophiles & nucleophiles • Types of organic reactions

Unit XIII: Hydrocarbons

Alkanes: nomenclature, isomerism, conformations (ethane), prep., reactions (halogenation, combustion, pyrolysis) Alkenes: nomenclature, structure, geometrical isomerism, prep., reactions (addition, Markownikoff’s rule, peroxide effect, ozonolysis, oxidation) Alkynes: nomenclature, structure, prep., reactions (acidity, addition) Aromatic hydrocarbons (benzene): structure, resonance, aromaticity, reactions (nitration, sulphonation, halogenation, Friedel-Crafts), directive influence, carcinogenicity

Unit XIV: Environmental Chemistry

• Pollution: air, water, soil • Reactions in atmosphere: smog, pollutants, acid rain, ozone depletion • Greenhouse effect, global warming • Industrial waste, green chemistry, pollution control strategies