AHSEC 1st Year Syllabus 2024-25 Chemistry

Assam Higher Secondary Education Council

Chemistry Syllabus for the year 2023-24
COURSE STRUCTURE CLASS–HS
First Year (THEORY) (2023-24)
Time: 3 Hours Total Marks70

S.No UNIT No. of Marks
Period
s
1 Some Basic Concepts of Chemistry 12 7
2 Structure of Atom 14 9
3 Classification of Elements and Periodicity in 8 6
Properties
4 Chemical Bonding and Molecular Structure 14 7
5 Chemical Thermodynamics 16 9
6 Equilibrium 14 7
7 Redox Reactions 6 4
8 Organic Chemistry: Some basic Principles 14 11
and Techniques
9 Hydrocarbons 12 10

TOTAL 70

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 non-
spontaneous 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 poly basic 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 hyper conjugation. Homolytic and heterolytic
fission of a covalent bond: free radicals, carbocations, carbanions, electrophiles and nucleophiles,
types of organic reactions.

: Hydrocarbons 12 Periods

Classification of Hydrocarbons
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, mechanismof 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.

***

PRACTI CALS

Evaluation Scheme for Examination Marks
Volumetric Analysis 08
Salt Analysis 10
Content Based Experiment 04
Project Work 04
Class record and viva 04
Total 30

PRACTICAL SYLLABUS Total
Periods: 60

Micro-chemical methods are available for several of the practical
experiments, wherever possible suchtechniques should be used.
A. Basic Laboratory Techniques

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

B. Characterization and Purification of Chemical Substances
1. Determination of melting point of an organic compound.
2. Determination of boiling point of an organic compound.
3. Crystallization of impure sample of any one of the following: Alum, Copper Sulphate, Benzoic Acid.
C. Experiments based on pH
a) Any one of the following experiments:
• Determination of pH of some solutions obtained from fruit juices, solution of known and
varied concentrations of acids, bases and salts using pH paper or universal indicator.
• Comparing the pH of solutions of strong and weak acids of same concentration.
• Study the pH change in the titration of a strong base using universal indicator.
b) Study the pH change by common-ion in case of weak acids and weak bases.
D. Chemical Equilibrium
One of the following experiments:

a) Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing
the concentration of either of the ions.
b) Study the shift in equilibrium between [Co(H2O)6]2+ and chloride ions by changing the
concentration of either of the ions.

E. Quantitative Estimation
i. Using a mechanical balance/electronic balance. ii.
Preparation of standard solution of Oxalic acid.
iii. Determination of strength of a given solution of Sodium hydroxide by titrating it against standard
solution of Oxalic acid.
iv. Preparation of standard solution of Sodium carbonate.
v. Determination of strength of a given solution of hydrochloric acid by titrating it against standard
Sodium Carbonate solution.
F. Qualitative Analysis

a) Determination of one anion and one cation in a given salt
Cations- Pb2+, Cu2+, As3+, Al3+, Fe3+, Mn2+, Ni2+, Zn2+, Co2+, Ca2+, Sr2+, Ba2+, Mg2+, NH+ 4
2- 2 3- , S3O 4 2-, S
3 3 , S 2-, NO 4 O 32-, N
3 O3 - , Cl-, Br -, I -, PO 3-
Anions – CO 44 CH3C3 OO- (Note: Insoluble salts excluded)

b) Detection of -Nitrogen, Sulphur, Chlorine in organic compounds.

c) PROJECTS
Scientific investigations involving laboratory testing and collecting information from other
sources.
A few suggested Projects
• Checking the bacterial contamination in drinking water by testing sulphide ion
• Study of the methods of purification of water

• Testing the hardness, presence of Iron, Fluoride, Chloride, etc.,
depending upon the regional variation in drinking water and study of
causes of presence of these ions above permissible limit (if any).
• Investigation of the foaming capacity of different washing soaps and the
effect of addition ofSodium carbonate on it
• Study the acidity of different samples of tea leaves.
• Determination of the rate of evaporation of different liquids
• Study the effect of acids andbases on the tensile strength of fibers.

• Study of acidity of fruit and vegetable juices.

Note: Any other investigatory project, which involves about 10 periods of work, can be
chosen with theapproval of the teacher.
Prescribed Books:
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.