Assam Board AHSEC Class 11 Chemistry Syllabus, Important Topics and Marking Scheme

Assam Board HS Chemistry Syllabus 2024: Chemistry topics are important as well as difficult to fully understand. Thus, it becomes crucial for students to be aware of any changes to or deletions from the Chemistry syllabus. Checking the recently released syllabus and comparing it to the prior syllabus is the best way to learn about the changes made to the curriculum.

To help AHSEC HS 1st year students of Class 11 science, we have provided the newly released Assam Board Class 11 Chemistry syllabus. This Assam HS Chemistry syllabus 2023–24 will be followed for the 2024 HS examination for Class 11. Students are advised to go through this article once to check the AHSEC HS Chemistry syllabus and paper pattern. The PDF is attached for free download.

AHSEC Chemistry HS 1st Course Structure 2023-24

HSEC Chemistry Syllabus For HS 1st Year

Theory Syllabus

Unit 1: Some Basic Concepts of Chemistry (12 Periods) 

General Introduction: Importance and scope of Chemistry. 

Nature of matter, laws of chemical combination, Dalton’s atomic theory: concept of elements, atoms and molecules. 

Atomic and molecular masses, mole concept and molar mass, percentage composition, empirical and molecular formula, chemical reactions, stoichiometry and calculations based on stoichiometry. 

Unit 2: Structure of Atom (14 Periods)

Discovery of Electron, Proton and Neutron, atomic number, isotopes and isobars. Thomson’s model and its limitations. Rutherford’s model and its limitations, Bohr’s model and its limitations, concept of shells and subshells, dual nature of matter and light, de Broglie’s relationship, Heisenberg uncertainty principle, concept of orbitals, quantum numbers, shapes of s, p and d orbitals, rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of atoms, stability of half-filled and completely filled orbitals.

Unit 3: Classification of Elements and Periodicity in Properties (08 Periods)

Significance of classification, brief history of the development of periodic table, modern periodic law and the present form of periodic table, periodic trends in properties of elements -atomic radii, ionic radii, inert gas radii, Ionization enthalpy, electron gain enthalpy, electronegativity, valency. Nomenclature of elements with atomic number greater than 100. 

Unit 4: Chemical Bonding and Molecular Structure (14 Periods) 

Valence electrons, ionic bond, covalent bond, bond parameters, Lewis structure, polar character of covalent bond, covalent character of ionic bond, valence bond theory, resonance, geometry of covalent molecules, VSEPR theory, concept of hybridization, involving s, p and d orbitals and shapes of some simple molecules, molecular orbital theory of homonuclear diatomic molecules(qualitative idea only), Hydrogen bond.

Unit 5: Chemical Thermodynamics (16 Periods)

Concepts of System and types of systems, surroundings, work, heat, energy, extensive and intensive properties,state functions. First law of thermodynamics -internal energy and enthalpy, heat capacity and specific heat, measurement of U and H, Hess’s law of constant heat summation, enthalpy of bond dissociation, combustion, formation, atomization, sublimation, phase transition, ionization, solution and dilution. 

Second law of Thermodynamics(brief introduction) 

Introduction of entropy as a state function, Gibb’s energy change for spontaneous and nonspontaneous processes, criteria for equilibrium. Third law of thermodynamics (brief introduction).

Unit 6: Equilibrium (14 Periods) 

Equilibrium in physical and chemical processes, dynamic nature of equilibrium, law of mass action, equilibrium constant, factors affecting equilibrium – Le Chatelier’s principle, ionic equilibrium- ionization of acids and bases, strong and weak electrolytes, degree of ionization, ionization of polybasic acids, acid strength, concept of pH, hydrolysis of salts (elementary idea), buffer solution, Henderson Equation, solubility product, common ion effect (with illustrative examples).

Unit 7: Redox Reactions (06 Periods) 

Concept of oxidation and reduction, redox reactions, oxidation number, balancing redox reactions, in terms of loss and gain of electrons and change in oxidation number, applications of redox reactions.

Unit 8: Organic Chemistry -Some Basic Principles and Techniques (14 Periods) 

General introduction, methods of purification, qualitative and quantitative analysis, classification and IUPAC nomenclature of organic compounds. Electronic displacements in a covalent bond: inductive effect, electromeric effect, resonance and hyperconjugation. Homolytic and heterolytic fission of a covalent bond: free radicals, carbocations, carbanions, electrophiles and nucleophiles, types of organic reactions.

Classification of Hydrocarbons (12 Periods)

Aliphatic Hydrocarbons: 

Alkanes – Nomenclature, isomerism, conformation (ethane only), physical properties, chemical reactions including free radical mechanism of halogenation, combustion and pyrolysis. Alkenes – Nomenclature, structure of double bond (ethene), geometrical isomerism, physical properties, methods of preparation, chemical reactions: addition of hydrogen, halogen, water, hydrogen halides (Markovnikov’s addition and peroxide effect), ozonolysis, oxidation, mechanism of electrophilic addition. Alkynes – Nomenclature, structure of triple bond (ethyne), physical properties, methods of preparation, chemical reactions: acidic character of alkynes, addition reaction of – hydrogen, halogens, hydrogen halides and water. 

Aromatic Hydrocarbons: 

Introduction, IUPAC nomenclature, benzene: resonance, aromaticity, chemical properties: mechanism of electrophilic substitution. Nitration, sulphonation, halogenation, Friedel Craft’s alkylation and acylation, directive influence of functional group in monosubstituted benzene. Carcinogenicity and toxicity.

Practical Syllabus 

Total Period: 60

Micro-chemical methods are available for several of the practical experiments, wherever possible such techniques should be used.

1. Basic Laboratory Techniques
2. Cutting glass tube and glass rod
3. Bending a glass tube
4. Drawing out a glass jet
5. Boring a cork

To check the complete AHSEC Chemistry HS 1st year practical syllabus click on the link below and download the full syllabus PDF. 

AHSEC Chemistry Practical HS 1st Marking Scheme 2024

Prescribed Textbook:

1. Chemistry Part – I, Class-XI, Published by NCERT. 
2. Chemistry Part – II, Class-XI, Published by NCERT. 
3. Laboratory Manual of Chemistry, Class XI, Published by NCERT.

Also Read:

NCERT Class 11 Revised Textbooks

NCERT Rationalised Content for Class 11