Assam HS 2nd Year Chemistry Syllabus 2025-26 : Download AHSEC Class 12 Chemistry Syllabus PDF

The Assam Higher Secondary Education Council (AHSEC) has officially released the AHSEC HS 2nd Year Chemistry Syllabus 2025–26 for Class 12 students. The syllabus has been designed to provide a deeper understanding of human, economic, and regional geography, along with practical applications through fieldwork and data analysis.

Students preparing for the HS Final Examination 2026 should thoroughly study this updated syllabus to focus on high-weightage units and practical topics. Teachers can also use it to plan lessons and design assessments in a structured manner.

HS 2nd Year Chemistry Syllabus 2025–26 – Overview

Particular	Details
Subject Name	Chemistry
Class	HS 2nd Year (Class 12)
Board	Assam Higher Secondary Education Council (AHSEC)
Exam Duration	3 Hours
Total Marks	100 (Theory + Practical)
Academic Year	2025–2026
Official Website	ahsec.assam.gov.in

Total Marks Distribution

Component	Marks
Theory Paper	70
Practical Work (Part II)	30
Grand Total	100 Marks

AHSEC Class 12 Chemistry Syllabus Overview (Theory – 70 Marks)

If you are preparing for your Class XII board exam, having a clear understanding of the complete Class 12 Chemistry Syllabus 2025 is extremely important. This detailed, easy-to-read breakdown includes the latest NCERT theory units, marks distribution, practical syllabus, experiments, and project list. Designed to help students score better, this article gives you everything in a simple, exam-focused format.

Below is the official unit-wise marks and period distribution:

S.No.	Chapter / Unit	Periods	Marks
1	Solutions	10	7
2	Electrochemistry	12	9
3	Chemical Kinetics	10	7
4	d- and f-Block Elements	12	7
5	Coordination Compounds	12	7
6	Haloalkanes and Haloarenes	10	6
7	Alcohols, Phenols and Ethers	10	6
8	Aldehydes, Ketones & Carboxylic Acids	10	8
9	Amines	10	6
10	Biomolecules	12	7
Total	—	—	70 Marks

Unit-Wise Class 12 Chemistry Syllabus (Detailed)

Unit 1: Solutions (10 Periods)

Key topics include:

• Types of solutions
• Concentration expressions
• Solubility of solids and gases
• Raoult’s Law
• Colligative properties
• Molecular mass determination
• Abnormal molecular masses
• Van’t Hoff factor

Unit 2: Electrochemistry (12 Periods)

Topics covered:

• Redox reactions
• EMF, standard electrode potential
• Nernst equation
• Gibbs energy & EMF relation
• Conductance, molar conductivity
• Kohlrausch’s law
• Electrolytic and galvanic cells
• Lead storage cell & fuel cell
• Corrosion

Unit 3: Chemical Kinetics (10 Periods)

Includes:

• Rate of reaction
• Factors affecting reaction rate
• Order and molecularity
• Rate law
• Integrated rate equations (0 & 1st order)
• Collision theory
• Arrhenius equation

Unit 4: d- and f-Block Elements (12 Periods)

Topics:

• Electronic configuration
• Properties of transition metals
• Trends in the first-row d-block
• Preparation & properties: K₂Cr₂O₇ and KMnO₄
• Lanthanoids: configuration, contraction
• Actinoids: comparison with lanthanoids

Unit 5: Coordination Compounds (12 Periods)

Includes:

• Ligands, coordination number
• Colour & magnetic properties
• IUPAC naming
• Werner’s theory, VBT, CFT
• Isomerism
• Uses in metallurgy, biology

Unit 6: Haloalkanes & Haloarenes (10 Periods)

Important topics:

• Nomenclature
• Nature of C–X bond
• Physical & chemical properties
• Optical rotation
• Substitution mechanisms
• Directive influence
• Environmental effects of DCM, CHCl₃, CCl₄, iodoform, freons, DDT

Unit 7: Alcohols, Phenols & Ethers (10 Periods)

Alcohols:

• Preparation, properties
• Mechanism of dehydration
  Phenols:
• Acidic nature
• Electrophilic substitution
  Ethers:
• Preparation and properties

Unit 8: Aldehydes, Ketones & Carboxylic Acids (10 Periods)

• Carbonyl group
• Preparation methods
• Nucleophilic addition mechanism
• Alpha hydrogen reactivity
• Acidic nature of carboxylic acids

Unit 9: Amines (10 Periods)

Includes:

• Classification
• Structure
• Preparation & properties
• Identification tests
• Diazonium salts and reactions

Unit 10: Biomolecules (12 Periods)

Topics:

• Carbohydrates: mono, di, polysaccharides
• Proteins and structures
• Enzymes & hormones
• Vitamins: types & functions
• Nucleic acids: DNA & RNA

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Class 12 Chemistry Practical Syllabus (30 Marks)

Component	Marks
Volumetric Analysis (Titration)	6
Salt Analysis	12
Content-Based Experiment	4
Project Work	4
Class Record & Viva	4
Total	30 Marks

Practical Experiments (60 Periods)

A. Surface Chemistry

• Prepare lyophilic & lyophobic sols
• Dialysis
• Emulsion stability

B. Chemical Kinetics

• Effect of concentration & temperature
• Clock reactions

C. Thermochemistry

• Enthalpy of dissolution
• Neutralization
• Hydrogen bonding

D. Electrochemistry

• Variation of cell potential

E. Chromatography

• Pigment separation
• Inorganic mixture separation

F. Preparation of Inorganic Compounds

• Mohr’s salt
• Potash alum
• Ferric oxalate

G. Organic Preparations

• Acetanilide
• Dibenzal acetone
• p-Nitroacetanilide
• Aniline dye

H. Tests for Functional Groups

• Alcohols, phenols, aldehydes, ketones, acids, amines

I. Biomolecule Tests

• Carbohydrates, proteins, fats

J. Titration

• KMnO₄ vs oxalic acid
• KMnO₄ vs Mohr’s salt

Recommended Books

• NCERT Chemistry Part I (Class 12)
• NCERT Chemistry Part II (Class 12)
• NCERT Chemistry Laboratory Manual

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FAQs – Class 12 Chemistry Syllabus

1. How many marks are allotted to Organic Chemistry?

Organic Chemistry units together carry around 26–28 marks.

2. Is chemical kinetics difficult?

No. With formula-based questions, it is one of the scoring chapters.

3. How to score full marks in Chemistry practicals?

Maintain a neat record book, practice titrations, and revise salt analysis regularly.

4. Are NCERT books enough?

Yes, NCERT theory + examples + exercises are essential for board exams.

Important Links

Class 12 Chemistry Syllabus PDF	Click Here
HS Class 12 Syllabus Home	Click Here
Official Website	Click Here