Bihar Board Class 12 Chemistry Weightage 2026 Unit and Chapter-Wise Mark Distribution

Bihar Board Class 12 Chemistry Weightage 2026 will help you to pick the important topics first based on the weightage of marks while doing the final preparation. The chemistry exam will be conducted for 100 marks, with 70 marks allocated to theory and 30 marks to practicals. Check details here.

Table of Contents

Bihar Board Class 12 Chemistry Weightage 2026 - Unit-wise
Bihar Board Class 12 Chemistry Syllabus 2025-26
BSEB 12th Chemistry Blueprint 2026

Bihar Board Class 12 Chemistry Weightage 2026 : To help you prepare effectively for your class 12 board exams, we have provided unit-wise weightage of marks for the Chemistry subjects. The weightage will help you in prioritizing important topics. For example, the unit with the highest weightage of marks, i.e., 8 marks, is P-Block Elements, followed by the 6-mark unit, i.e., Aldehydes, Ketones, and Carboxylic Acids. Similarly, there are many units of 5 marks each, which you can pick first while preparing for the final exam. You can also download Bihar Board Class 12 Chemistry Previous Year Question Papers to get a better understanding of the pattern of the paper and the weightage of marks. Referring to these papers, along with the Bihar Board Class 12 Chemistry Weightage 2026 provided here, will give you a clear strategy for exam preparation.

Bihar Board Class 12 Chemistry Weightage 2026 - Unit-wise

BSEB 12th Chemistry theory paper consists of 16 units, including p-block Elements, which is of 8 marks, and Aldehydes, Ketones, and Carboxylic Acids, which is of 6 marks, with the most weightage, while units like Polymers and Chemistry in Everyday Life are of 3 marks each. The total marks allocated for the exam are 100, of which 70 marks are for the theory paper and 30 marks for the practical assessment. All the units of the BSEB 12th Chemistry paper have been mentioned in the table below.

Unit	Title	Marks
1	Solid State Electrical and magnetic properties, Packing efficiency, voids, number of atoms per unit cell in a cubic unit cell, point defects, etc.	4
2	Solutions Osmotic pressure, determination of molecular masses using colligative properties, Elevation of boiling point, depression of freezing point, abnormal molecular mass, etc.	5
3	Electrochemistry Kohlrausch’s Law, lead accumulator, Conductance in electrolytic solutions, specific, variations of conductivity with concentration, etc.	5
4	Chemical Kinetics Integrated rate equations and half-life, the concept of collision theory (elementary idea, no mathematical treatment), etc.	5
5	Surface Chemistry Brownian movement, electrophoresis, Lyophobic multimolecular and macromolecular colloids; properties of colloids; Tyndall effect, coagulation, emulsion-types of emulsions, etc.	4
6	General Principles and Process of Isolation of Elements Occurrence and principles of extraction of aluminium, copper, zinc and iron, Principles and methods of extraction – concentration, oxidation, reduction – electrolytic method and refining; etc.	3
7	P-Block Elements Halides PCl3, Ozone, Sulphur-allotropic forms; Phosphorus – allotropic forms, Preparation properties and uses of sulphur-dioxide, etc.	8
8	d-and-f-Block Elements Magnetic properties, interstitial compounds, Metallic character, ionization enthalpy, preparation and properties of K2Cr2O7 and KMnO4, etc.	5
9	Coordination Compounds IUPAC nomenclature of mononuclear coordination compounds. Bonding, Introduction, ligands, coordination number, Werner’s theory, VBT, and CFT; structure and stereoisomerism, etc.	3
10	Haloalkanes and Haloarenes Nomenclature, nature of C-X bond, physical and chemical properties, substitution reactions, etc.	4
11	Alcohols, Phenols, and Ethers Mechanism of dehydration, physical and chemical properties, uses, uses with special reference to methanol and ethanol, etc.	4
12	Aldehydes, Ketones, and Carboxylic Acids Nomenclature, nature of carbonyl group, methods of preparation, physical, uses, methods of preparation, etc.	6
13	Organic Compounds Containing Nitrogen Classification, structure, methods of preparation, secondary and tertiary amines, etc.	4
14	Biomolecules Monosaccharides (glucose and fructose), polysaccharides (starch, cellulose, glycogen) importance, etc.	4
15	Polymers Biodegradable and non-biodegradable polymers, etc, Some important polymers: natural and bakelite, rubber, etc.	3
16	Chemistry In Everyday Life Tranquillizers, antiseptics, disinfectants, antacids, antihistamines, artificial sweetening agents, etc.	3
Total		70

Understanding the Bihar Board Class 12 Chemistry Syllabus 2025-26 topic-wise weightage is very important for your exam preparations. You can maximize your scores by focusing on high-weightage topics such as p-Block, d, and f-Block Elements and Electrochemistry & Chemical Kinetics. Similarly, topics such as coordination compounds and organic compounds containing nitrogen have a lower weightage but should not be overlooked.

BSEB 12th Chemistry Blueprint 2026

BSEB 12th Chemistry consists of two sections, i.e., A and B. Section A has 70 objective-type questions, each worth one mark, out of which 35 have to be answered, which is worth 35 marks. Section B has 10 short-answer questions of 2 marks each and 3 long-answer questions of 5 marks each. Also, there is no negative marking. Check the blueprint below:

Sections	Types of Questions	Number of questions	Marks Allotted
A	Objective-type questions	35 out of 70	1 * 35 = 35
B	Short-answer and long-answer questions	10 out of 20 + 3 out of 6	2 * 10 + 5 * 3 = 35

We hope the information added above is helpful for your final preparation. You can keep visiting the page for the latest information about the Bihar Board Class 12 Chemistry Weightage 2026 Unit and Chapter-Wise Mark Distribution.