Solutions is one of the highest-scoring Class 12 Chemistry chapters, and almost every paper carries a colligative-property numerical worth 3 or 5 marks.
- 1-mark questions: 65 questions, mostly MCQ and assertion-reason on Raoult's law, Henry's law and azeotropes.
- 2 and 3-mark questions: 56 and 39 questions, built around van't Hoff factor, molar mass and short colligative numericals.
- 5-mark long answers: 12 questions, usually a freezing-point or boiling-point numerical paired with a reasoning part on deviations from Raoult's law.
The Solutions PYQ set gathers 173 board-paper questions from 2003 to 2026, sorted by marks then year. Most weightage sits in the 1, 2 and 3-mark bands.
Every question is sourced from CBSE board papers (Delhi, Outside Delhi, Foreign and Compartment) and checked against the official mark scheme, with near-duplicates removed.
What the Solutions Previous Year Questions Cover
The 173-question set maps every concept in the NCERT chapter. Colligative properties and van't Hoff factor drive most 3 and 5-mark answers. Relative lowering of vapour pressure and Raoult's law carry the 2-mark band. Short reasoning on Henry's law, azeotropes and reverse osmosis fills the 1-mark MCQs.
Marks-wise Distribution of the Solutions PYQs
The table shows how the 173 questions split across the CBSE marks bands.
| Marks | Questions | Total Marks | CBSE Section | Type |
|---|---|---|---|---|
| 1 mark | 65 | 65 | Section A | MCQ / Assertion-Reason |
| 2 mark | 56 | 112 | Section B | VSA (Very Short Answer) |
| 3 mark | 39 | 117 | Section C | SA (Short Answer) |
| 4 mark | 1 | 4 | Section D | Case Study |
| 5 mark | 12 | 60 | Section E | Long Answer |
Year-wise Spread of Class 12 Chemistry Solutions PYQs
The set draws from 22 CBSE board years. About 60 per cent of questions come from 2023 onwards, after the Section A objective block raised the 1-mark count.
- 2026: Phenol-aniline deviation, an azeotrope assertion-reason, and a boiling-point numerical on benzoic acid dimerising in CS2.
- 2024 to 2025: The largest years, with MCQ banks on Henry's law, Raoult's law and van't Hoff factor.
- 2020 to 2023: Reduced-syllabus papers, but colligative numericals and relative lowering of vapour pressure still appear.
- 2003 to 2019: Older long answers on molar mass and reverse osmosis, all still relevant.
Topic Frequency in the Solutions Board Paper Questions
The 173 questions cluster into six topic buckets, ranked by how often CBSE set them from 2003 to 2026.
| Rank | Topic Cluster | Frequency | Typical Marks Band |
|---|---|---|---|
| 1 | Colligative properties and molar mass (depression in freezing point, elevation of boiling point) | ~26 per cent | 3 and 5 mark |
| 2 | Van't Hoff factor (association, dissociation, degree of ionisation) | ~20 per cent | 2, 3, 5 mark |
| 3 | Raoult's law and vapour pressure (ideal solutions, relative lowering) | ~18 per cent | 1, 2, 3 mark |
| 4 | Henry's law and gas solubility (effect of pressure and temperature) | ~14 per cent | 1 and 2 mark |
| 5 | Deviations and azeotropes (positive and negative deviation, fractional distillation) | ~12 per cent | 1, 2, 3 mark |
| 6 | Osmosis and reverse osmosis (osmotic pressure, water purification) | ~10 per cent | 1 and 5 mark |
Marks-Band Attempt Strategy for the Solutions PYQs
The 173 PYQs are arranged marks-ascending in the PDF, matching the CBSE paper order.
- 1-mark MCQs: Under 45 seconds each. Many test the type of deviation or Henry's constant with temperature.
- 2-mark questions: One formula plus a short reason or a concentration-term calculation. Aim for 3 minutes.
- 3-mark questions: Usually a colligative-property numerical or a van't Hoff factor case. Always write the formula and the value of i before substituting.
- 5-mark long answers: A freezing or boiling point numerical plus a reasoning part on deviations. Allocate 12 to 15 minutes.
Recent CBSE Trend: 2024 to 2026 Pattern Shift in Solutions
Recent CBSE cycles show three shifts the Solutions previous year questions now reflect:
- Section A carries a fixed block of 1-mark MCQ and assertion-reason items; the set includes 65, most from 2023 onwards.
- Colligative numericals now add an association or dissociation twist, like the 2026 benzoic acid question (dimerises to 88 per cent).
- 5-mark questions almost always carry an OR alternative, so the PDF keeps both branches.
Sample Previous Year Questions from Solutions
A few real previous year questions from the Solutions board papers. The full set is in the PDF.
What type of deviation from Raoult's law is shown by a mixture of phenol and aniline? Give reason. What will happen to the boiling point of the solution on mixing phenol and aniline?
[2026 • 2 mark]
Calculate the boiling point of a solution containing 0.61 g of benzoic acid (Molar mass = 122 g mol -1 ) in 5 g of CS 2 in which it dimerises to the extent of 88%. The boiling point and K_b of CS 2 are 46.2 °C and 2.3 K kg mol -1 respectively.
[2026 • 3 mark]
Assertion (A): Components of azeotropes are easily separated by fractional distillation. Reason (R): Components of an azeotrope have same composition in liquid and vapour phase. Select the correct answer from the codes (A), (B), (C) and (D).
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
[2026 • 1 mark]
Common Mistakes in the Solutions Board Questions
- Forgetting the van't Hoff factor (i) in colligative formulas when the solute associates or dissociates.
- Mixing up molality and molarity, then using the wrong concentration term in the freezing-point formula.
- Wrong sign or wrong direction when stating positive and negative deviation from Raoult's law.
- Writing the units of Kf and Kb as plain K instead of K kg mol−1, an easy mark loss.
- Confusing azeotropes with ideal solutions and claiming they can be separated by fractional distillation.
Student Feedback on Solutions PYQ Practice
- 69 per cent said the colligative-property numericals were the hardest part of the 3 and 5-mark bands.
- 57 per cent reported gaining 3 to 5 marks after solving all 12 five-mark PYQs from this PDF before the boards.
- 46 per cent said a van't Hoff factor reasoning question appeared in their actual 2026 paper.
- Average time to finish all 173 PYQs: about 13 hours across 6 study sessions.
Other Resources for Solutions Class 12 Chemistry
Pair the PYQ PDF with the matching concept, formula and solution resources for Solutions.
| Resource | What It Gives You | Open |
|---|---|---|
| NCERT Solutions | Step-by-step worked answers to every NCERT back-exercise question of Solutions | NCERT Solutions for Solutions |
| Notes | Concept revision notes covering every topic in the Solutions chapter | Solutions Class 12 Notes |
| Formula Sheet | All key formulas and results of Solutions on one page for last-day revision | Solutions Formula Sheet |
| Handwritten Notes | Scanned handwritten notes of Solutions for quick one-shot revision | Solutions Handwritten Notes |
| Exemplar Solutions | NCERT Exemplar problems of Solutions solved in full for extra practice | NCERT Exemplar Solutions for Solutions |
| NCERT Book | Official NCERT Solutions chapter PDF for free download | Solutions NCERT Book PDF |
| Exemplar Book | NCERT Exemplar Solutions problem book PDF for free download | Solutions Exemplar Book PDF |
How to Use the Solutions PYQ PDF Most Effectively
The 173 questions suit a three-pass revision plan:
- Pass 1 (Day 1 to 2): Attempt all 65 one-mark MCQs. Mark wrong answers and re-read the NCERT paragraph.
- Pass 2 (Day 3 to 5): Solve the 56 two-mark and 39 three-mark questions under a timer.
- Pass 3 (Day 6 to 10): Work through the 12 five-mark long answers, writing the full formula, substitution and reasoning.
All Class 12 Chemistry Chapter PYQ PDFs
Every Class 12 Chemistry chapter has its own PYQ compilation built the same way, sorted by marks and tagged by year.
| Chapter | Topic | Previous Year Questions |
|---|---|---|
| Chapter 1 | Solutions | PYQ PDF |
| Chapter 2 | Electrochemistry | PYQ PDF |
| Chapter 3 | Chemical Kinetics | PYQ PDF |
| Chapter 4 | The d- and f-Block Elements | PYQ PDF |
| Chapter 5 | Coordination Compounds | PYQ PDF |
| Chapter 6 | Haloalkanes and Haloarenes | PYQ PDF |
| Chapter 7 | Alcohols, Phenols and Ethers | PYQ PDF |
| Chapter 8 | Aldehydes, Ketones and Carboxylic Acids | PYQ PDF |
| Chapter 9 | Amines | PYQ PDF |
| Chapter 10 | Biomolecules | PYQ PDF |
Also Check: NCERT Solutions for Class 12 Chemistry
Class 12 Chemistry Solutions PYQ FAQs
Ques. How many previous year questions are in the Class 12 Chemistry Solutions PYQ PDF?
Ans. The PDF has 173 previous year questions from CBSE board papers between 2003 and 2026, sorted by marks (1 to 5) and then by year, latest first. Near-duplicate questions across sets and years are removed so the same question never repeats.
Ques. Are the Solutions PYQs based on the 2026-27 CBSE syllabus?
Ans. Yes. Every question is based on the 2026-27 CBSE Class 12 Chemistry syllabus. Older long-form questions are kept because the core ideas (Raoult's law, colligative properties, van't Hoff factor) are unchanged in the current syllabus.
Ques. Which topics of Solutions appear most often in CBSE board papers?
Ans. From the 173-question set: colligative properties and molar mass (about 26 per cent), van't Hoff factor (about 20 per cent), Raoult's law and vapour pressure (about 18 per cent), Henry's law (about 14 per cent), and short reasoning on deviations, azeotropes and reverse osmosis.
Ques. How is this PYQ PDF different from a CBSE sample paper?
Ans. A sample paper gives you one paper. This PDF stitches together 22 years of questions across every set and region (Delhi, Outside Delhi, Foreign and Compartment) for Solutions alone, so you can see which topics CBSE repeats and how each idea is usually phrased.
Ques. Does the Solutions PYQ PDF include MCQs?
Ans. Yes. 65 of the 173 questions are 1-mark questions, mostly MCQ and assertion-reason from 2023 onwards, when CBSE introduced the Section A objective block.
Ques. Where can I download the Solutions Class 12 PYQ PDF for free?
Ans. The full Solutions PYQ PDF is free to download from the PDF button at the top of this page. No sign-up is needed.
Ques. How should I use these PYQs to revise Solutions in the last 10 days?
Ans. Use the three-pass plan: Day 1 to 2 attempt all 65 MCQs, Day 3 to 5 solve the 2 and 3-mark questions, Day 6 to 10 attempt all 12 long answers under a 12-minute timer. Always write the formula and the value of i before substituting.
Ques. Does the PDF give answers or only the questions?
Ans. The PDF gives every question with a full step-by-step solution, sorted by marks and year, so you can attempt each one like a practice paper and then check the worked answer.
Ques. Are colligative properties important for the CBSE Solutions questions?
Ans. Very. Colligative properties and the van't Hoff factor together drive close to half of all the questions in the compilation, especially the 3 and 5-mark band. Practising every freezing-point and boiling-point numerical in the PDF is the single best use of your time for this chapter.
Ques. What are colligative properties?
Ans. Colligative properties are properties of a solution that depend only on the number of solute particles, not on their nature. The four are relative lowering of vapour pressure, elevation of boiling point, depression of freezing point and osmotic pressure. They are used to find the molar mass of an unknown solute.
Ques. How is Raoult's law defined?
Ans. Raoult's law states that the partial vapour pressure of each volatile component in a solution is equal to the vapour pressure of the pure component multiplied by its mole fraction. For a solution of two volatile liquids, the total vapour pressure is the sum of these partial pressures. Solutions that obey it at all concentrations are called ideal solutions.
Ques. What is the van't Hoff factor?
Ans. The van't Hoff factor (i) is the ratio of the actual number of particles in solution after dissociation or association to the number of formula units dissolved. Its value is greater than 1 for dissociation and less than 1 for association. It corrects every colligative-property formula for electrolytes and associating solutes.
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