NEET (UG) · Chemistry, Class 12
Solutions: NEET PYQ, 2018–2026
Solutions (Chemistry, Class 12) has been asked 11 times in the 7 NEET papers from 2018, 2020, 2021, 2023, 2024, 2025 and 2026: about 1.6 questions a paper, 4% of all Chemistry questions. It is the 15th most-asked of 21 Chemistry chapters. NEET 2026 had 2 from it. Last checked 28 October 2026.
Questions per paper
Year by year.
| Year | Questions |
|---|---|
| 2018 | 0 |
| 2020 | 2 |
| 2021 | 2 |
| 2023 | 0 |
| 2024 | 2 |
| 2025 | 3 |
| 2026 | 2 |
From 2021 to 2024 each paper had 200 questions (a Section B with a choice); the others had 180.
Inside the chapter
Topics asked most.
- Raoult's law6
- Colligative properties3
- Concentration terms1
- van't Hoff factor1
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10 Solutions questions to practise.
Our own questions, written in the NEET pattern and checked, each with an explanation. Pick an option to see the answer.
Q1 · Chemistry · Solutions
When Al₂(SO₄)₃ dissolves completely in water, how many ions are produced per formula unit, which is the van't Hoff factor i if the solute dissociates completely?
Answer: (C)
The van't Hoff factor i gives the ratio of actual particles to formula units for a solute. For complete dissociation, i equals the total number of ions formed per formula unit. Writing the dissociation equation Al₂(SO₄)₃ → 2Al³⁺ + 3SO₄²⁻ shows 5 ions, so i = 5 for ideal complete dissociation. Balance the equation first, then add the ions.
Q2 · Chemistry · Solutions
What is the osmotic pressure of a 0.1 M aqueous solution of glucose at 27 °C? (R = 0.083 L bar mol⁻¹ K⁻¹)
Answer: (B)
π = CRT = 0.1 mol L⁻¹ × 0.083 L bar mol⁻¹ K⁻¹ × 300 K = 2.49 bar. Glucose is a non-electrolyte, so no van’t Hoff factor is needed.
Q3 · Chemistry · Solutions
200 mg of a protein is dissolved in water to make 50 mL of solution. At 300 K the osmotic pressure of this solution is 2.5 mm Hg. Assuming the protein is a non-electrolyte and the solution behaves ideally, what is the approximate molar mass of the protein? (R = 0.0821 L atm K⁻¹ mol⁻¹; 1 atm = 760 mm Hg)
Answer: (A)
For a dilute solution of a non-electrolyte, π = CRT = (w/M)(RT/V), so M = wRT/(πV). Convert units first. w = 200 mg = 0.200 g. V = 50 mL = 0.050 L. π = 2.5/760 = 3.29 × 10⁻³ atm. M = (0.200 × 0.0821 × 300)/(3.29 × 10⁻³ × 0.050) = 4.926/1.645 × 10⁻⁴ ≈ 3.0 × 10⁴ g mol⁻¹. Missing the mL to L conversion gives about 30, missing mm Hg to atm gives about 39, and missing mg to g gives about 3 × 10⁷.
Q4 · Chemistry · Solutions
A non-volatile solute is dissolved in a volatile solvent. Which statement correctly describes the vapour above the solution?
Answer: (A)
A non-volatile solute has zero vapour pressure, so it cannot enter the gas phase. The vapour is therefore pure solvent vapour, and its partial pressure is reduced according to Raoult's law as p_solvent = x_solvent p°_solvent.
Q5 · Chemistry · Solutions
A mixture of chloroform and acetone shows negative deviation from Raoult's law because:
Answer: (A)
The chloroform molecule forms a hydrogen bond with the oxygen of acetone. These A–B attractions are stronger than the A–A and B–B attractions, so each component escapes less readily, the vapour pressure is lower than Raoult’s law predicts, and the deviation is negative.
Q6 · Chemistry · Solutions
A sample of sulphuric acid is 98 % H₂SO₄ by mass and has a density of 1.84 g mL⁻¹. What is its molarity? (H₂SO₄ = 98 g mol⁻¹)
Answer: (B)
Mass of 1 L of solution = 1000 mL × 1.84 g mL⁻¹ = 1840 g. Mass of H₂SO₄ in it = 0.98 × 1840 = 1803.2 g, which is 1803.2/98 = 18.4 mol. So the molarity is 18.4 mol L⁻¹.
Q7 · Chemistry · Solutions
A solution is prepared by mixing 46 g of ethanol (C₂H₅OH, molar mass 46 g mol⁻¹) with 54 g of water (molar mass 18 g mol⁻¹). What is the mole fraction of ethanol in the solution?
Answer: (C)
Mole fraction of a component is its moles divided by the total moles of all components in the solution. First convert each mass to moles using n = mass / molar mass: ethanol gives 1 mol and water gives 3 mol. The total is 4 mol, so the mole fraction of ethanol is 1/4 = 0.25. The mole fractions of all components in a solution must add up to 1, which gives a check: 0.25 + 0.75 = 1.
Q8 · Chemistry · Solutions
Four aqueous solutions of equal molality (0.1 m) are prepared: (I) glucose, (II) KNO₃, (III) Na₃PO₄, (IV) CaCl₂. Assuming complete dissociation of the electrolytes, which of the following gives the correct order of increasing freezing point?
Answer: (C)
ΔTf = i·Kf·m, and at equal molality ΔTf is proportional to i. The solute with the largest i lowers the freezing point the most. Na₃PO₄ → 3Na⁺ + PO₄³⁻ gives i = 4. CaCl₂ → Ca²⁺ + 2Cl⁻ gives i = 3. KNO₃ → K⁺ + NO₃⁻ gives i = 2. Glucose does not ionise, so i = 1. The largest depression, and so the lowest freezing point, belongs to Na₃PO₄, and the smallest depression, so the highest freezing point, to glucose. The order is III < IV < II < I.
Q9 · Chemistry · Solutions
When liquids A and B are mixed, the mixture becomes warm and its volume is slightly less than the sum of the two volumes taken. Such a solution is expected to:
Answer: (B)
Heat evolved (Δ_mixH < 0) and a contraction in volume (Δ_mixV < 0) show that A–B attractions are stronger than A–A and B–B attractions. The molecules escape less readily, so the vapour pressure is lower than Raoult’s law predicts: negative deviation. A solution with a large negative deviation forms a maximum boiling azeotrope, as nitric acid and water do.
Q10 · Chemistry · Solutions
At a certain temperature the vapour pressures of pure liquids A and B are 300 mm Hg and 500 mm Hg. What is the total vapour pressure of an ideal solution made by mixing 2 mol of A with 3 mol of B?
Answer: (A)
x(A) = 2/5 = 0.4 and x(B) = 3/5 = 0.6. By Raoult’s law and Dalton’s law, p(total) = x(A) p°(A) + x(B) p°(B) = 0.4 × 300 + 0.6 × 500 = 120 + 300 = 420 mm Hg.
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All 11 real NEET questions from Solutions.
The questions from the actual papers, with the official answer and an explanation for each — chapter by chapter, or as full timed papers.
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About Solutions in NEET.
How many questions come from Solutions in NEET?
Solutions (Chemistry, Class 12) has been asked 11 times in the 7 NEET papers from 2018, 2020, 2021, 2023, 2024, 2025 and 2026: about 1.6 questions a paper, 4% of all Chemistry questions. It is the 15th most-asked of 21 Chemistry chapters. NEET 2026 had 2 from it.
Which topics of Solutions are asked most in NEET?
Raoult's law (6), Colligative properties (3), Concentration terms (1), van't Hoff factor (1), counted over the papers from 2018–2026.
Is Solutions important for NEET 2027?
It is in the syllabus in force, so it can be asked. By past papers it ranks 15 of 21 in Chemistry; use that to decide how much time it gets, not whether to study it.
Where can I solve Solutions NEET previous year questions?
On Nikaalle, free: sign up and practise every past NEET question from Solutions with an explanation for each, or sit the full papers timed. The ten questions on this page are our own, written in the same pattern.
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