Source-safe PYQ archive

CBSE Chemistry PYQ archive

Search official CBSE Class XII Chemistry paper provenance, source metadata, parsing state, and review status before anything becomes student practice. Generated-original PrepAI practice is tracked separately and must pass review before DPP, mocks, or assignments can use it.

Official PYQ provenance

Generated-original practice

Review status visible

No copied question text

How past papers work in Prep

Imported PYQs stay review-gated until parsing and source metadata pass.

The archive links directly to official CBSE papers and chapter coordinates. Every practice question in Prep is written for Prep and checked for units, step-by-step marking, and syllabus fit before it appears in your daily set or mocks.

Trust constraints

PrepAI shows how the study loop is constrained before asking for trust.

No unverifiable launch claims

Source-safe

Official sources guide structure and coordinates; PrepAI content stays coordinate-based.

Deterministic tools

Chemistry calculators and paper compilation use local rules, not runtime AI guesses.

Answer-masked

Answers, explanations, and rubrics stay locked until the student commits a response.

Review-gated

Questions must pass content review before DPP, practice, assignment, or mock use.

Secure rendering

Formula rendering uses KaTeX with trust:false and unsafe math commands blocked.

CBSE Class XII Chemistry, 2025-26

Syllabus blueprint (70 marks)

Curriculum marks across Part 1 (Solutions 7M, Electrochemistry 9M, Chemical Kinetics 7M, d- and f-Block Elements 7M, Coordination Compounds 7M) and Part 2 Organic Chemistry (33M) totaling 70 theory marks. Study times, revision priorities and marks per hour are our estimates, not past-paper analysis or a prediction of your score.

Part 1: 37M

Part 2: 33M

Total Theory: 70M

Available Study Hours Filter

Coverage (our estimate)

21 / 70M

Marks per hour (our estimate)

4.67 M/h

Chapters in Window

3 / 10

Direct Revision Workbenches

Physical Chem Calculators 25 Named Reactions & Mechanisms Part 1 practice paper (35 marks)

The paper aims for 35 marks. Its preview shows the actual total.

Priority	Chapter & Blueprint Weight	Time (our estimate)	Marks per hour (our estimate)	Suggested subtopics & NCERT coordinate	Practice Route
#1 In 5h	Coordination Compounds 7MCBSE-12-CHEM-CH5 · Part 1: Physical & Inorganic	1.5h	4.67 M/h	CFT octahedral splitting, VBT hybridisation, and IUPAC nomenclature2M / 3M Conceptual + Case-Based · NCERT Part 1 > Ch 5 > Sec 5.3 & 5.5	Build Coordination Paper
#2 In 5h	Solutions 7MCBSE-12-CHEM-CH1 · Part 1: Physical & Inorganic	1.5h	4.67 M/h	Colligative properties, van't Hoff factor i, and Raoult's law3M Numerical + 2M Conceptual · NCERT Part 1 > Ch 1 > Sec 1.6 & 1.7	Open Solutions Calculators
#3 In 5h	Chemical Kinetics 7MCBSE-12-CHEM-CH3 · Part 1: Physical & Inorganic	1.5h	4.67 M/h	First-order integrated rate law, half-life, and Arrhenius Ea slope3M Numerical + 4M Case Study · NCERT Part 1 > Ch 3 > Sec 3.3 & 3.4	Open Kinetics Calculators
Next Window	d- and f-Block Elements 7MCBSE-12-CHEM-CH4 · Part 1: Physical & Inorganic	1.5h	4.67 M/h	Lanthanoid contraction, Cr/Cu anomalies, and KMnO4 / K2Cr2O7 redox2M / 3M Reasoning + 5M Composite · NCERT Part 1 > Ch 4 > Sec 4.3 & 4.4	Build d/f-Block Paper
Next Window	Biomolecules 7MCBSE-12-CHEM-CH10 · Part 2: Organic & Biomolecules	1.5h	4.67 M/h	Glucose structure reactions, peptide linkage, protein denaturation, DNA vs RNA4M Case-Based + 1M MCQ · NCERT Part 2 > Ch 10 > Sec 10.1 & 10.2	Build Biomolecules Paper
Next Window	Electrochemistry 9MCBSE-12-CHEM-CH2 · Part 1: Physical & Inorganic	2.0h	4.50 M/h	Nernst equation numericals, Kohlrausch law, and Faraday electrolysis3M / 5M Stepwise Numerical + 1M MCQ · NCERT Part 1 > Ch 2 > Sec 2.3 & 2.4	Open Electrochemistry Calculators
Next Window	Amines 6MCBSE-12-CHEM-CH9 · Part 2: Organic & Biomolecules	1.5h	4.00 M/h	Hoffmann bromamide, Gabriel phthalimide, carbylamine, and basicity in aqueous phase3M Basicity / Distinction + 2M Diazonium · NCERT Part 2 > Ch 9 > Sec 9.4 & 9.6	Open Named Reactions Workbench
Next Window	Aldehydes, Ketones and Carboxylic Acids 8MCBSE-12-CHEM-CH8 · Part 2: Organic & Biomolecules	2.5h	3.20 M/h	Aldol / Cannizzaro mechanisms, Tollens' / Fehling's tests, and pKa order5M Organic Conversion + Named Reactions · NCERT Part 2 > Ch 8 > Sec 8.4 & 8.9	Open Named Reactions Workbench
Next Window	Haloalkanes and Haloarenes 6MCBSE-12-CHEM-CH6 · Part 2: Organic & Biomolecules	2.0h	3.00 M/h	SN1 vs SN2 stereochemistry, Finkelstein / Swarts, and aryl halide reactivity2M / 3M Mechanism & Distinction · NCERT Part 2 > Ch 6 > Sec 6.5 & 6.6	Open Named Reactions Workbench
Next Window	Alcohols, Phenols and Ethers 6MCBSE-12-CHEM-CH7 · Part 2: Organic & Biomolecules	2.0h	3.00 M/h	Reimer-Tiemann, Kolbe's reaction, Williamson synthesis, and acid dehydration3M Conversion + 2M Acidity Reasoning · NCERT Part 2 > Ch 7 > Sec 7.4 & 7.6	Open Named Reactions Workbench

Source: CBSE Chemistry (043) curriculum, 2025-26, Class XII course structure, page 9. These are syllabus marks, not past-paper frequencies. Not affiliated with or endorsed by CBSE.

Read the CBSE 2025-26 Chemistry curriculum

Metadata-only PYQ map

CBSE Class XII Chemistry Part 1 Mapped PYQ Registry

Past-board source records are organized by chapter, learning outcome, marks weight, and review state. PrepAI shows source coordinates and outcome signals here, not copied PYQ text.

Mapped PYQ references101

Pilot chapters10

Estimated theory marks mapped: 0 / 70

Local-only solved checklist for mapped source references. It saves in this browser as prepai_public_pyq_checklist; no backend profile rows or answer keys are created.

0 / 22 references checked

CBSE-12-CHEM-CH1

Solutions

7 marks

CBSE-12-CHEM-CH2

Electrochemistry

9 marks

CBSE-12-CHEM-CH3

Chemical Kinetics

7 marks

CBSE-12-CHEM-CH4

d- and f-Block Elements

7 marks

CBSE-12-CHEM-CH5

Coordination Compounds

6 marks

CBSE-12-CHEM-CH6

Haloalkanes and Haloarenes

6 marks

CBSE-12-CHEM-CH7

Alcohols, Phenols and Ethers

6 marks

CBSE-12-CHEM-CH8

Aldehydes, Ketones and Carboxylic Acids

8 marks

CBSE-12-CHEM-CH9

Amines

6 marks

CBSE-12-CHEM-CH10

Biomolecules

7 marks

Outcome source drawer

Concentration units and molality

LO-SOL-01

NCERT coordinate: NCERT Part 1 > Chapter 1 > Solutions > Concentration terms
Locator metadata only; page numbers and extracted PYQ text require parser QA.

Source references

CBSE 2024 Chemistry archive

2 marks

2024 / Class XII Chemistry source set

Numerical concentration item - exact question number pending extraction QA

Bloom: apply / Extraction pending

Mark mapped practice solved locallyAdds 2 marks to the browser-only tracker after the student completes the original-practice permutation.

CBSE 2023 Chemistry archive

2 marks

2023 / Class XII Chemistry source set

Solution concentration item - exact question number pending extraction QA

Bloom: apply / Extraction pending

Mark mapped practice solved locallyAdds 2 marks to the browser-only tracker after the student completes the original-practice permutation.

Generate original practice paper Open active-recall practice

Stop gate

Official source records guide outcome mapping. Student practice uses original permutations and answer-masked reveal flow until review approves extracted source use.

Metadata-only PYQ ledger: official source coordinates, outcome mapping, and review status without copied question text.

Source-safe search surface

Filter CBSE Chemistry source records by year, chapter, provenance type, and review status. Official CBSE PYQ provenance is a source record; generated-original practice is a separate PrepAI content record.

CBSE source page

Search source metadata

Year

Chapter

Provenance type

Review status

Showing 12 of 12 source records

Official CBSE PYQ provenance

2026

CHEMISTRY 2026 source archive

cbse-2026-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 19.9 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2026

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2026

CHEMISTRY 2025-COMPTT source archive

cbse-2025-comptt-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 1.78 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2025-COMPTT

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2025

CHEMISTRY 2025 source archive

cbse-2025-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 24.3 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2025

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2025

CHEMISTRY 2024-COMPTT source archive

cbse-2024-comptt-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 1.55 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2024-COMPTT

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2024

CHEMISTRY 2024 source archive

cbse-2024-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 27.6 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2024

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2024

CHEMISTRY 2023-COMPTT source archive

cbse-2023-comptt-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 10.0 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2023-COMPTT

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2023

CHEMISTRY 2023 source archive

cbse-2023-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 19.3 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2023

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2023

CHEMISTRY 2022-COMPTT source archive

cbse-2022-comptt-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 4.23 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2022-COMPTT

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Official CBSE PYQ provenance

2022

CHEMISTRY 2022 source archive

cbse-2022-class-xii-chemistry

Review status

Parsing check pending

All Chemistry chapters

Source metadata

CBSE official question-paper portal - ZIP - 18.1 MB - Official archive link verified

CBSE archive > Class XII > Chemistry > 2022

Student visibility

Source link only; imported PYQ text is not eligible for DPP, mocks, or practice yet.

Open official archive

Generated-original practice

Original

Colligative properties original practice set

prepai-original-solutions-colligative-v1

Review status

Student-eligible after review

Solutions

Source metadata

Outcome locator CBSE-12-CHEM-CH1 - generated-original flag true - review manifest required

Chapter 1 > Colligative properties > van't Hoff factor

Student visibility

Eligible only after content review; explanation and rubric stay masked until commit.

Generated-original practice

Original

Nernst equation original practice set

prepai-original-electrochem-nernst-v1

Review status

Content review in progress

Electrochemistry

Source metadata

Outcome locator CBSE-12-CHEM-CH2 - misconception tags pending reviewer sign-off

Chapter 2 > Nernst equation > concentration cell reasoning

Student visibility

Not student-visible until QA review approves response, units, and rubric.

Generated-original practice

Original

First-order kinetics original practice set

prepai-original-kinetics-first-order-v1

Review status

Student-eligible after review

Chemical Kinetics

Source metadata

Outcome locator CBSE-12-CHEM-CH3 - deterministic calculation fixture attached

Chapter 3 > Integrated rate laws > first-order half-life

Student visibility

Eligible for DPP and mocks only through approved-question selection.

Coverage: 9 official CBSE Chemistry archive links plus generated-original review examples. Official PYQ provenance records prove source coordinates; generated-original practice records prove original PrepAI item review.

Official PYQ provenance

The archive stores official source coordinates, file links, metadata, and review status. It does not treat extracted paper text as launch-ready student practice.

Generated-original practice

PrepAI practice items are original, outcome-tagged, misconception-tagged, and review-gated before they can appear in DPPs, assignments, or mocks.

Reviewed before practice

Each source record moves from indexed link to reviewed original practice. Until review is complete, only the official CBSE archive link and chapter coordinates appear.

Reviewed practice bank

Timed practice is separate from the official source archive and only uses reviewed items returned by the practice API. If the backend is unavailable, the public source archive above remains readable.

Loading reviewed practice items...