| Science NCERT Exemplar Solutions (Class 6th to 10th) | ||||||||||||||
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| 6th | 7th | 8th | 9th | 10th | ||||||||||
| Science NCERT Exemplar Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Science NCERT Exemplar Solutions (Class 12th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
Class 11th Chemistry NCERT Exemplar Solutions
1. Some Basic Concepts Of Chemistry
This chapter introduces the fundamental concepts of chemistry, the science of matter and its transformations. It covers the classification of matter, properties, and standard units of measurement (SI Units). Key concepts include the **Laws of Chemical Combination** (e.g., Law of Conservation of Mass), Dalton's Atomic Theory, and the concepts of atoms, molecules, and ions. Crucially, the **mole concept** ($\textsf{1 mole} = 6.022 \times 10^{23}$ particles) and molar mass are explained, enabling quantitative calculations in chemistry, such as stoichiometry and expressing solution concentrations (e.g., molarity $\textsf{M}$).
2. Structure Of Atom
This chapter delves into the microscopic world of the atom, detailing its composition and structure. It traces the discovery of **subatomic particles** (electrons, protons, neutrons) and the evolution of atomic models from Thomson and Rutherford to **Bohr's model** for the hydrogen atom. The wave-particle duality of matter (De Broglie's hypothesis $\lambda = \frac{\textsf{h}}{\textsf{p}}$) and the uncertainty principle are introduced. The chapter explains atomic orbitals using **quantum numbers** and describes how electrons are filled in orbitals following rules like the Aufbau principle, Hund's rule, and Pauli exclusion principle, providing a quantum mechanical understanding of atomic structure.
3. Classification Of Elements And Periodicity In Properties
This chapter explains how elements are organized systematically in the **Periodic Table**, reflecting their properties and chemical behaviour. It discusses the historical attempts at classification (Dobereiner, Newlands, Mendeleev) leading to the development of the **Modern Periodic Table**, based on the atomic number. The arrangement of elements into periods and groups is explained, correlating with electronic configurations. The **periodicity of properties** such as atomic size, ionic size, ionisation enthalpy, electron gain enthalpy, electronegativity, and metallic/non-metallic character is discussed, showing predictable trends across periods and down groups, which helps in understanding chemical properties of elements.
4. Chemical Bonding And Molecular Structure
This crucial chapter explains how atoms combine to form molecules and the forces holding them together (**chemical bonds**). It covers different types of bonds: **ionic bonds** (electron transfer), **covalent bonds** (electron sharing), and coordinate bonds. Concepts like **Lewis structures**, formal charge, bond parameters, resonance, and polarity are discussed. Bonding theories like **VSEPR Theory** for predicting molecular shapes, **Valence Bond Theory (VBT)** explaining hybridization and orbital overlap, and **Molecular Orbital Theory (MOT)** are introduced to understand molecular structure and bonding. Intermolecular forces (Van der Waals, hydrogen bonding) are also covered, influencing physical properties.
5. States Of Matter
This chapter discusses the different physical states of matter – solid, liquid, and gas – and the role of **intermolecular forces** in determining these states. It focuses particularly on the **gaseous state**, explaining the fundamental **gas laws** (Boyle's Law $\textsf{PV = constant}$, Charles's Law $\frac{\textsf{V}}{\textsf{T}} = \textsf{constant}$) and the **Ideal Gas Equation** ($\textsf{PV = nRT}$). Dalton's law of partial pressures and Graham's law of diffusion are covered. The chapter introduces the **Kinetic Theory of Gases** to explain gas behaviour from a molecular perspective and discusses the properties of liquids like vapour pressure, viscosity, and surface tension.
6. Thermodynamics
**Thermodynamics** is the branch of chemistry that deals with energy changes during physical and chemical processes. This chapter introduces fundamental concepts like system, surroundings, and state functions. The **First Law of Thermodynamics** ($\Delta \textsf{U} = \textsf{Q} + \textsf{W}$), a statement of energy conservation, and the concept of **enthalpy** ($\Delta \textsf{H}$) are central. Thermochemistry, including enthalpy of formation, combustion, and bond enthalpy, and **Hess's Law** are covered. The **Second Law of Thermodynamics** introduces **entropy** ($\Delta \textsf{S}$) and the spontaneity of processes. **Gibbs Free Energy** ($\Delta \textsf{G} = \Delta \textsf{H} - \textsf{T}\Delta \textsf{S}$) is used to predict spontaneity and relates to equilibrium.
7. Equilibrium
This chapter focuses on the state of **equilibrium** in reversible processes, both physical and chemical, where the forward and reverse rates are equal. It covers **chemical equilibrium**, introducing the **Law of Mass Action** and the **equilibrium constant** ($\textsf{K}_\text{c}$ and $\textsf{K}_\text{p}$), which indicates the extent of the reaction. **Le Chatelier's principle** is used to predict the effect of changes in concentration, temperature, or pressure on the equilibrium position. **Ionic equilibrium** discusses acid-base theories, the pH scale ($\textsf{pH} = -\textsf{log}[\textsf{H}^+]$), hydrolysis of salts, buffer solutions, solubility product, and the common ion effect.
8. Redox Reactions
**Redox reactions** involve simultaneous **oxidation** and **reduction**, fundamentally representing the transfer of electrons. This chapter defines oxidation and reduction in terms of electron transfer and changes in **oxidation numbers**. Rules for assigning oxidation numbers are explained. Various types of redox reactions are discussed. A key skill taught is the **balancing of redox reactions** using methods like the oxidation number method and the ion-electron method. The chapter also introduces the concept of electrochemical cells (Galvanic cells and Electrolytic cells) where redox reactions are used to generate or consume electrical energy, linking chemistry and electricity.
9. Hydrogen
This chapter is dedicated to the element **hydrogen**, the first element in the periodic table. It discusses its unique position, isotopes (protium, deuterium, tritium), and different forms (e.g., ortho and para hydrogen). Methods for its preparation (laboratory and industrial) and its physical and chemical properties are covered. Important compounds of hydrogen, such as **water** (structure, properties, hard/soft water) and **hydrogen peroxide** ($\textsf{H}_2\textsf{O}_2$), are discussed. Different types of hydrides (ionic, covalent, metallic) and the potential of hydrogen as a future fuel are also explored, highlighting its versatility and importance.
10. The S-Block Elements
This chapter focuses on the chemistry of the **s-block elements**, comprising Alkali Metals (Group 1) and Alkaline Earth Metals (Group 2). Their electronic configurations and general characteristics, such as atomic/ionic radii, ionization enthalpy, hydration enthalpy, and metallic properties, are discussed, explaining trends within the groups. The methods of preparation, physical and chemical properties, and uses of important compounds of these elements (e.g., Sodium Hydroxide $\textsf{NaOH}$, Sodium Carbonate $\textsf{Na}_2\textsf{CO}_3$, Calcium Oxide $\textsf{CaO}$, Calcium Sulphate $\textsf{CaSO}_4$) are explained. The anomalous behaviour of the first element of each group is also highlighted.
11. The P-Block Elements
This chapter provides a detailed study of the chemistry of the **p-block elements**, located in Groups 13 to 18 (excluding Helium). It discusses their general electronic configurations, oxidation states, trends in properties (e.g., atomic radii, ionization enthalpy, electronegativity), and chemical reactivity. The chemistry of specific groups is explored, focusing on Boron family (Group 13) and Carbon family (Group 14). Important compounds of Boron (e.g., borax, boric acid, diborane) and Carbon (e.g., oxides of carbon, allotropes) and Silicon (silicates, zeolites) are discussed. The anomalous behaviour of the first element in each group and the diagonal relationship with elements in the next group are also covered.
12. Organic Chemistry: Some Basic Principles And Techniques
This chapter is an essential introduction to **organic chemistry**, the study of carbon compounds. It explains the unique bonding characteristics of carbon (tetravalency, catenation, multiple bonds) leading to the vast diversity of organic compounds. The **IUPAC nomenclature** system for naming organic compounds is introduced. Concepts like isomerism, types of chemical reactions, bond fission (homolytic, heterolytic), reactive intermediates (carbocations, carbanions, free radicals), and electronic effects (inductive, resonance, hyperconjugation) influencing reactivity are discussed. Methods for purification (crystallisation, distillation, chromatography) and qualitative/quantitative analysis of organic compounds are also covered, providing foundational knowledge and practical techniques.
13. Hydrocarbons
This chapter focuses on **hydrocarbons**, organic compounds containing only carbon and hydrogen atoms. They are classified into **aliphatic hydrocarbons** (saturated alkanes, unsaturated alkenes and alkynes) and **aromatic hydrocarbons**. The nomenclature, isomerism, methods of preparation, physical properties, and characteristic chemical reactions (e.g., substitution in alkanes, addition in alkenes and alkynes, combustion, pyrolysis) for each class are discussed in detail. The unique structure and stability of **benzene**, the simplest aromatic hydrocarbon, and the concept of aromaticity are explained, providing a fundamental understanding of these crucial families of organic compounds.
14. Environmental Chemistry
This chapter addresses the chemical aspects of the environment and human impact on it, focusing on **environmental pollution**. It discusses pollution of the atmosphere, hydrosphere, and lithosphere, identifying major pollutants and their sources (e.g., industrial emissions, vehicular exhaust, agricultural runoff). Concepts like **acid rain**, **ozone layer depletion**, **greenhouse effect**, and **global warming** are explained from a chemical perspective. Strategies for preventing and controlling environmental pollution and the importance of **green chemistry** for designing environmentally friendly processes are highlighted, connecting chemistry to real-world environmental challenges and the need for sustainable practices for a cleaner India.
Sample Paper
This entry represents a **Sample Paper** designed to help students practice and assess their understanding of the Class 11th Chemistry syllabus covered in the NCERT Exemplar Solutions. It contains a variety of practice questions covering concepts and topics from Chapters 1 through 14. Working through this sample paper allows students to test their knowledge retention, application of concepts, and time management skills under exam conditions, enabling effective revision and assessment of their preparedness for examinations in Chemistry. This resource helps students consolidate their learning and improve problem-solving abilities.