BSEB 12th Chemistry Weightage 2026 - Check chapter wise weightage

Each chapters and topics in BSEB 12th Chemistry exam has different weightage. Knowing about the weightage helps students prioritise topics accordingly. Check here BSEB 12th Chemistry Weightage 2026!

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The Bihar Board of Secondary Education (BSEB) will conduct the BSEB 12th Chemistry Exam 2026 for 100 marks. The theory examination is held for 3 hours and 15 minutes and carries 70 marks, while 30 marks are reserved for practical assessment. The passing mark for each chemistry theory and practical exam component is 30%. While preparing for the Bihar Board 12th Chemistry Exam 2026 you should know which topics are given major emphasis in terms of weightage to gain more marks.

Chapters such as p-block Elements (11.43%) and Aldehydes, Ketones, and Carboxylic Acids (8.57%) carry the highest weightage in the Bihar Board Class 12 Chemistry theory paper and should be given priority during preparation. In Physical Chemistry, units like Electrochemistry, Solutions, and Chemical Kinetics contribute 7.14% each, making them important scoring areas. At the same time, you should not completely ignore lower-weightage units, as questions are distributed across the entire syllabus. Additionally, Section A alone carries 50% of the total theory marks, making objective-type questions a crucial component for maximizing scores.

By placing your main focus on the units/chapters with the greatest weightage, you will cover a large portion of your syllabus and will therefore drastically increase your aggregate Chemistry score. You can see additional details of the weightage of units for the BSEB 12th Chemistry Exam 2026 below.

BSEB 12th Chemistry Exam Pattern 2026

The BSEB Class 12 Chemistry theory paper will be conducted for 70 marks and will include 96 questions divided into two sections. You must attempt questions strictly as per the prescribed pattern. Section A carries the highest weightage of 35 marks, making objective questions a key scoring area. More details below:

Section	Question Type	Questions to Attempt	Marks per Question	Total Marks	Weightage
Section A	Objective-type	35 out of 70	1 mark	35	50%
Section B	Short-answer	10 out of 20	2 marks	20	28.57%
	Long-answer	3 out of 6	5 marks	15	21.43%
Total	—	—	—	70 Marks	100%

Also Read: BSEB 12th Chemistry Exam Pattern 2026

BSEB 12th Chemistry Unit-Wise Weightage 2026

The BSEB Class 12 Chemistry theory paper is worth 70 marks and includes questions from 16 different units. Unit 7 (p-block Elements) has the highest weightage of any unit, with 11.43%, making it particularly important for scoring. Understanding unit weightage can help students plan their revision more strategically.

Unit	Chapters	Marks	Weightage
Unit 1	Solid State	04	5.71%
Unit 2	Solutions	05	7.14%
Unit 3	Electrochemistry	05	7.14%
Unit 4	Chemical Kinetics	05	7.14%
Unit 5	Surface Chemistry	04	5.71%
Unit 6	General Principles and Processes of Isolation of Elements	03	4.29%
Unit 7	p-block Elements	08	11.43%
Unit 8	d and f-block Elements	05	7.14%
Unit 9	Coordination Compounds	03	4.29%
Unit 10	Haloalkanes and Haloarenes	04	5.71%
Unit 11	Alcohols, Phenols, and Ethers	04	5.71%
Unit 12	Aldehydes, Ketones, and Carboxylic Acids	06	8.57%
Unit 13	Organic Compounds Containing Nitrogen	04	5.71%
Unit 14	Biomolecules	04	5.71%
Unit 15	Polymers	03	4.29%
Unit 16	Chemistry in Everyday Life	03	4.29%
Total	—	70 Marks	100%

Also Read: Bihar Board 12th Chemistry Syllabus 2026

BSEB 12th Chemistry Chapter-Wise Weightage 2026

The Bihar Board Class 12 Chemistry theory paper is conducted for 3 hours and 15 minutes and carries a total of 70 marks. The syllabus is divided into 16 units, covering Physical, Inorganic, and Organic Chemistry. Among all units, p-block Elements, ketones, and carboxylic acids, and key Physical Chemistry chapters carry relatively higher weightage, making them important from an exam perspective.

Unit	Chapter	Key Topics Covered	Marks	Weightage
Unit 1	Solid State	Types of solids, unit cell, packing efficiency, defects, electrical & magnetic properties	04	5.71%
Unit 2	Solutions	Types of solutions, concentration terms, solubility, colligative properties, abnormal molecular mass	05	7.14%
Unit 3	Electrochemistry	Redox reactions, conductivity, Kohlrausch’s law, electrochemical cells, Nernst equation, corrosion	05	7.14%
Unit 4	Chemical Kinetics	Rate of reaction, order & molecularity, rate law, half-life, collision theory	05	7.14%
Unit 5	Surface Chemistry	Adsorption, catalysis, enzymes, colloids, emulsions, Tyndall effect	04	5.71%
Unit 6	General Principles and Processes of Isolation of Elements	Methods of extraction, metallurgy of Al, Cu, Zn, Fe	03	4.29%
Unit 7	p-block Elements	Groups 15–18, properties, compounds of nitrogen, phosphorus, sulphur, halogens, noble gases	08	11.43%
Unit 8	d and f-block Elements	Transition metals, properties, KMnO₄, K₂Cr₂O₇, lanthanoids, actinoids	05	7.14%
Unit 9	Coordination Compounds	Ligands, nomenclature, bonding theories, isomerism, applications	03	4.29%
Unit 10	Haloalkanes and Haloarenes	Nomenclature, reactions, mechanisms, environmental effects of halogen compounds	04	5.71%
Unit 11	Alcohols, Phenols, and Ethers	Preparation, properties, reactions, identification tests, uses	04	5.71%
Unit 12	Aldehydes, Ketones, and Carboxylic Acids	Carbonyl chemistry, nucleophilic addition, acidity, preparation, uses	06	8.57%
Unit 13	Organic Compounds Containing Nitrogen	Amines, diazonium salts, reactions, identification, uses	04	5.71%
Unit 14	Biomolecules	Carbohydrates, proteins, vitamins, enzymes, DNA & RNA	04	5.71%
Unit 15	Polymers	Classification, polymerisation methods, biodegradable polymers	03	4.29%
Unit 16	Chemistry in Everyday Life	Medicines, food additives, soaps & detergents	03	4.29%
Total	—	—	70	100%

Also Read: BSEB 12th Chemistry Deleted Syllabus 2026

BSEB 12th Chemistry Internal Assessment Weightage 2026

The BSEB 12th Chemistry Internals, which include experiments, practical records, and viva, carry 30 marks out of 100. In this assessment, experiments hold the highest weightage of 50%, making them the most crucial component. You must secure a minimum of 30% marks overall by combining theory and practical scores in order to pass the exam.

Component	Marks	Weightage
Experiments	15	50%
Practical Record	5	16.67%
Viva Voce	5	16.67%
Attendance / Project	5	16.67%
Total	30	100%

Also Read: Bihar Board 12th Previous Year Question Papers

How to Score High using BSEB 12th Chemistry Weightage 2026 ?

Given below are the exam-focused points to help you score high using the BSEB 12th Chemistry Weightage 2026:

When preparing for this exam, the chapters that account for a significant portion of the mark allocation should be given priority. By prioritizing them, you will increase your chances of earning the highest possible score.
Since Section A accounts for half of the total marks allotted to theory, you should concentrate especially on this section and regularly practice responding to objective-type questions in order to receive more easy and quick marks.
While it's important to concentrate on high-weightage units, you also need to make sure that you consider the entire syllabus and practice all of the material equally. You have an equal chance of receiving marks for each of the sixteen units in the syllabus. Low-weightage units must therefore be treated with the same importance as the other high-weightage chapters.
Don't forget about the practical/internal assessment component, which makes up 30 of the final score. If you do well in experiments, reports, and viva, you will increase your overall score and raise your chances of getting a higher grade.