ISC Class 12 Chemistry Paper Pattern
The ISC Class 12 Chemistry theory paper (Paper I) is 70 marks in three hours, with 21 compulsory questions in four sections, A to D, of 1, 2, 3 and 5 marks. The practical, project and file are another 30 marks.
- 70marks, theory paper
- 3 h + 15 minwriting time and reading time
- 30 markspractical
Theory paper (Paper I): 70 marks
| Section | Questions | Marks | What it asks |
|---|---|---|---|
| Section A | Q1: fourteen sub-parts of 1 mark | 14 | multiple-choice, assertion-reason, fill-in-the-blank and case-based items across physical, inorganic and organic chemistry |
| Section B | Q2 to Q11: 10 questions of 2 marks | 20 | short answers, equations and numericals |
| Section C | Q12 to Q18: 7 questions of 3 marks | 21 | numericals, mechanisms, reactions and explanations |
| Section D | Q19 to Q21: 3 questions of 5 marks | 15 | long answers: conversions, mechanisms and numericals |
| Total | 21 questions, all compulsory | 70 |
The 2026 board paper has an internal choice in one question each of Sections B, C and D; the 2027 specimen paper has it in two questions each.
What the question paper says
- There are twenty-one questions in four sections; answer all questions. Internal choices are given in a few questions of Sections B, C and D.
- All working, including rough work, must be on the same sheet as, and beside, the rest of the answer.
- Balanced equations must be given wherever possible, and diagrams where they help. In numericals all essential working must be shown.
- The paper prints the data to use: R = 8.314 J K⁻¹ mol⁻¹ (also 1.987 cal and 0.0821 dm³ atm K⁻¹ mol⁻¹), 1 l atm = 1 dm³ atm = 101.3 J, 1 faraday = 96,500 coulombs and Avogadro’s number 6.023 × 10²³.
The practical and project marks
The practical component is 30 marks: the practical examination carries 15, the project work 10 and the practical file 5.
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Common questions
How many marks is the ISC Class 12 Chemistry paper?
70 marks for theory in three hours, and 30 marks for the practical, project and file.
What is the section-wise marks distribution of ISC Chemistry?
Section A is 14 one-mark sub-parts (14), Section B is ten 2-mark questions (20), Section C is seven 3-mark questions (21) and Section D is three 5-mark questions (15): 70 in all.
What data is given in the ISC Chemistry question paper?
The front page gives the gas constant (8.314 J K⁻¹ mol⁻¹, 1.987 cal, 0.0821 dm³ atm K⁻¹ mol⁻¹), 1 l atm = 101.3 J, 1 faraday = 96,500 coulombs and Avogadro’s number 6.023 × 10²³.
Are balanced equations compulsory in ISC Chemistry?
The instructions say balanced equations must be given wherever possible and diagrams wherever they are helpful, with all essential working shown in numericals.
Keep reading
Checked against the printed instructions of the 2026 board papers and the 2027 specimen papers, and CISCE’s ISC 2027 syllabus. Last checked 2026-10-16.