CBSE Class XI Chemistry Syllabus 2026 – 27

Rationale

The second phase of Secondary stage is the most crucial stage of school education because at this juncture specialised discipline based, content oriented courses are introduced. Students reach this stage after 10 years of general education and opt for Chemistry with a purpose of pursuing their career in basic sciences or professional courses like medicine, engineering, technology and to study courses in applied areas of science and technology at tertiary level. Therefore, there is a need to provide the learners with sufficient conceptual background of Chemistry, which will make them competent to meet the challenges of academic and professional courses after this stage.

The new and updated curriculum is based on a disciplinary approach with rigour and depth ensuring that the syllabus is not heavy and at the same time it is comparable to that at the international level. The pedagogy of Chemistry has undergone tremendous changes in recent times. To keep pace with the developments in Chemistry, many new areas like green chemistry, material science, biomolecules, and industrial chemistry deserve to be an integral part of the chemistry syllabus at this stage. In addition, the nomenclature of elements and compounds; symbols, and units of physical quantities, recommended by scientific bodies like IUPAC and CGPM also need to be incorporated in the updated syllabus. The proposed syllabus takes due care to address these issues.

Objectives

The curriculum of Chemistry at the second phase of Secondary stage has been designed to:

• equip the learners with tools to understand the working of Chemistry rather than mere facts of it;
• develop the necessary conceptual foundations of chemistry and ability to apply them to real life situations;
• enable the learners to represent chemical phenomena at macroscopic, molecular, and symbolic levels;
• make the learners identify patterns and form connections that underlie various chemical phenomena;
• prepare the learners to contribute to frontier research areas related to climate change, environmental issues, materials science, biology and medicine etc.:
• inculcate problem solving skills in the learners and integrate life skills and values in the context of chemistry; and
• apprise learners of the interface of chemistry with other disciplines of science such as physics, biology, geology, engineering etc.

CLASS XI

THEORY

Time: 3 Hours     Total Marks: 70

Importance of Chemistry, Nature of Matter, Properties of Matter and their Measurement, Uncertainty in Measurement, Laws of Chemical Combination, Dalton's Atomic Theory, Atomic and Molecular Masses, Mole Concept and Molar Masses, Percentage Composition, Stoichiometry and Stoichiometric Calculations.

Discovery of Sub-atomic Particles, Atomic Models, Developments Leading to the Bohr’s Model of Atom, Bohr’s Model for Hydrogen Atom, Towards Quantum Mechanical Model of the Atom, Quantum Mechanical Model of Atom.

Why we Need to Classify Elements? Genesis of Periodic Classification, Modern Periodic Law and the Present Form of Periodic Table, Nomenclature of Elements with Atomic Number > 100, Electronic Configuration of Elements and the Periodic Table, Electronic Configuration of Elements and Types of Elements: s-, p-, d-, f- Blocks, Periodic Trends in Properties of Elements.

Kossel-Lewis Approach to Chemical Bonding, Ionic or Electrovalent Bond, Bond Parameters, The Valence Shell Electron Pair Repulsion (VSEPR) Theory, Valence Bond Theory, Hybridisation, Molecular Orbital Theory, Bonding in Some Homonuclear Diatomic Molecules, Hydrogen Bonding.

Thermodynamic Terms, Applications, Measurement of ∆U and ∆H: Calorimetry, Enthalpy Change, and ∆H of a Reaction – Reaction Enthalpy, Enthalpies for Different Types of Reactions, Spontaneity, Gibbs Energy Change and Equilibrium.

Equilibrium in Physical Processes, Equilibrium in Chemical Processes – Dynamic Equilibrium, Law of Chemical Equilibrium and Equilibrium Constant, Homogeneous Equilibria, Heterogeneous Equilibria, Applications of Equilibrium Constants, Relationship between Equilibrium Constant K, Reaction Quotient Q and Gibbs Energy G, Factors Affecting Equilibria, Ionic Equilibrium in Solution, Acids, Bases and Salts, Ionization of Acids and Bases, Buffer Solutions, Solubility Equilibria of Sparingly Soluble Salts.

Classical Idea of Redox Reactions – Oxidation and Reduction Reactions, Redox Reactions in Terms of Electron Transfer Reactions, Oxidation Number, Redox Reactions and Electrode Processes.

General Introduction, Tetravalence of Carbon: Shapes of Organic Compounds, Structural Representations of Organic Compounds, Classification of Organic Compounds, Nomenclature of Organic Compounds, Isomerism, Fundamental Concepts in Organic Reaction Mechanism, Methods of Purification of Organic Compounds, Qualitative Analysis of Organic Compounds, Quantitative Analysis

Classification, Alkanes, Alkenes, Alkynes, Aromatic Hydrocarbon, Carcinogenic and Toxicity.

Note: The following topics are included in the syllabus but will be assessed only formatively to reinforce understanding without adding to summative assessments. This reduces academic stress while ensuring meaningful learning. Schools can integrate these with existing chapters as they align well. Relevant NCERT textual material is enclosed for reference.

1. s & p Block Elements
   Electronic configuration, atomic & Ionic radii, Ionization Enthalpy, Hydration Enthalpy and general trends in physical and chemical properties of s and p block elements across the periods and down the groups; unique behavior of the first element in each group.
2. The Gaseous State
   Qualitative treatment of Gas laws, Ideal gas equation and deviations from it.