SolutionsNEET MCQs with solutions
Solutions covers colligative properties (RLVP, elevation in boiling point, depression in freezing point, osmotic pressure), Raoult's law, Henry's law, molarity, molality, mole fraction and van't Hoff factor. NEET tests numerical problems on colligative properties and Raoult's law deviations heavily.
- Class
- 12 Chemistry
- Free on this page
- 24 questions
- In the RankUp app
- 552 questions
- ELITE questions
- 249
- NCERT topics
- 11
Practise 24 questions
Tap an option to check it. Questions from every NCERT topic in this chapter, from easy to hard.
Q1Important PYQ Mixed Concepts
One mole of a non-electrolyte solute is dissolved in three moles of water. The relative lowering of vapour pressure of the solution is
Not quite — the answer is A.
Relative lowering of vapour pressure equals mole fraction of solute. xsolute = 1/(1+3) = 0.25. Option B (0.20) traps students who use 1/5. Option C (0.33) traps those who use 1/3. Option D (0.75) is the solvent mole fraction.
Q2Important PYQ Mixed Concepts
At the same temperature, the Henry's law constants are: HCHO = 1.83×10⁻⁵ kbar, CH₄ = 0.413 kbar, CO₂ = 1.67 kbar, Ar = 40.3 kbar. Their order of solubility from highest to lowest is
Not quite — the answer is A.
Solubility is inversely proportional to KH. Smaller KH means higher solubility. HCHO has the smallest KH so it is most soluble; Ar has the largest so it is least soluble. Option B reverses the relationship entirely.
Q3Grand Test
At the same temperature, gas B has the lowest Henry's law constant KH among several gases. Compared with gases having larger KH values, gas B will generally have:
Not quite — the answer is C.
From Henry's law (p = KH × x), at fixed partial pressure, x = p/KH. A smaller KH gives a larger dissolved mole fraction and hence greater solubility in water. Gas B, with the lowest KH, is therefore the most soluble. Options A, B and D each incorrectly apply or ignore the inverse relationship between KH and solubility.
Q4Grand Test
A 0.20 M non-electrolyte solution is diluted to 0.10 M at the same temperature. The osmotic pressure of the resulting solution compared with the original is:
Not quite — the answer is B.
For a non-electrolyte, π = CRT. At constant temperature, osmotic pressure is directly proportional to molar concentration. When concentration is halved from 0.20 M to 0.10 M, osmotic pressure is also halved. Option A would require doubling of concentration. Options C and D do not follow from the linear relationship π ∝ C.
Q5Mixed Revision
A solution contains a non-volatile solute of molecular mass M₂. Which expression gives its molar mass in terms of osmotic pressure π, mass m₂, volume V and temperature T?
Not quite — the answer is B.
For a dilute solution, π = (m₂/M₂V)RT. Rearranging: M₂V π = m₂RT, so M₂ = m₂RT/(πV). Options A, C and D result from incorrect rearrangements of the osmotic pressure equation.
Q6Mixed Revision
Camphor is often used in molecular-mass determination by freezing-point depression because:
Not quite — the answer is A.
A high Kf (cryoscopic constant) gives a larger freezing-point depression for the same molality, making small differences in molar mass detectable. Camphor has Kf ≈ 40 K kg mol⁻¹, far higher than water or benzene.
Q7Reverse Osmosis and Applications
In reverse osmosis, the solvent flows from:
Not quite — the answer is A.
In normal osmosis, solvent moves from pure solvent to solution. In reverse osmosis, external pressure exceeding osmotic pressure forces solvent back — from solution to pure solvent. Option B describes normal osmosis. Options C and D are physically incorrect.
Q8Reverse Osmosis and Applications
A red blood cell is placed in a hypertonic solution. Which of the following correctly describes the outcome?
Not quite — the answer is C.
In hypertonic solution, osmotic pressure outside > inside cell. Water moves out of the cell (exosmosis) → cell shrinks (crenation). Option A (swelling) occurs in hypotonic solution. Option D (bursting) occurs in hypotonic solution when the cell absorbs excess water.
Q9Types of Solutions
Which of the following is a true solution?
Not quite — the answer is A.
True solutions are homogeneous mixtures with particle size less than 1 nm; milk and sulphur sol are colloids, smoke is a heterogeneous dispersion.
Q10Types of Solutions
Which type of solution is air?
Not quite — the answer is B.
Air is a homogeneous mixture of gases (N₂, O₂, Ar, CO₂), making it a gas-in-gas solution; gas-in-liquid would require a liquid solvent like water.
Q11Vapour Pressure of Liquid Solutions
Which law states that the partial vapour pressure of a volatile component in a solution is directly proportional to its mole fraction?
Not quite — the answer is A.
Raoult's Law: p = p⁰ × x, where x is the mole fraction of that component. Henry's Law applies to gases dissolving in liquids, not vapour pressure of solution components. Dalton's Law deals with total pressure of gas mixtures.
Q12Vapour Pressure of Liquid Solutions
According to Raoult's Law, the partial vapour pressure of a component in an ideal solution is directly proportional to its
Not quite — the answer is B.
Raoult's Law: p₁ = p⁰₁ × x₁ — mole fraction (x₁) is the proportionality variable, not mass or molarity. Molarity is a common trap because it seems concentration-based, but Raoult's Law is defined strictly in mole fraction terms.
528 more questions on this chapter are waiting in the app
Every one with a detailed explanation, plus flashcards and chapter tests.
Get RankUp on Google PlayQ13Colligative Properties
Which of the following is the best definition of a colligative property?
Not quite — the answer is B.
Colligative properties depend solely on the number of solute particles, not their chemical identity. Option A is wrong as chemical nature is irrelevant. Option D adds an incorrect condition.
Q14Colligative Properties
Which of the following is NOT a colligative property?
Not quite — the answer is B.
Electrical conductivity depends on the nature of ions (charge, mobility), not merely particle count — so it is not colligative. All other options depend only on solute particle number.
Q15Expressing Concentration of Solutions
Which concentration term is independent of temperature?
Not quite — the answer is A.
Molality is defined as moles of solute per kg of solvent — both are mass-based measurements unaffected by temperature; molarity, normality, and volume percent all involve volume which changes with temperature.
Q16Expressing Concentration of Solutions
Which concentration term represents moles of solute per litre of solution?
Not quite — the answer is B.
Molarity = moles of solute ÷ volume of solution in litres; molality uses kg of solvent not litres, mole fraction uses mole ratio, mass percent uses mass ratio.
Q17Solubility
Which of the following factors affect the solubility of a solid in a liquid?
Not quite — the answer is A.
NCERT states solubility of solids depends on temperature and nature of solute and solvent; pressure has negligible effect on solid solubility — making option B a strong trap for students who confuse solid and gas solubility rules.
Q18Solubility
For most solid solutes dissolved in liquid solvents, solubility increases with:
Not quite — the answer is B.
Most solid dissolutions are endothermic — increasing temperature shifts equilibrium toward dissolution, increasing solubility; pressure has negligible effect on solids, and surface area affects rate not equilibrium solubility.
Q19Abnormal Molar Mass
Abnormal molar mass is observed when a solute undergoes association or dissociation in solution. Which of the following is the correct reason for this?
Not quite — the answer is B.
Abnormal molar mass arises because colligative properties depend on particle count. Association or dissociation changes actual particle number, so the molar mass calculated from colligative data differs from the formula molar mass. Option A, C, D describe unrelated phenomena.
Q20Abnormal Molar Mass
When a solute dissociates in solution, why is the observed molar mass lower than the theoretical molar mass?
Not quite — the answer is C.
Molar mass is back-calculated from M = Kf × w / (ΔTf × W). Greater ΔTf (from more particles due to dissociation) gives a smaller M_observed. Option D is opposite — dissociation increases effective molality, not decreases it.
Q21Ideal and Non Ideal Solutions
Ethyl bromide (C₂H₅Br) and ethyl iodide (C₂H₅I) form a nearly ideal solution. Which of the following best explains this?
Not quite — the answer is A.
C₂H₅Br and C₂H₅I are structurally similar alkyl halides — similar size, shape, and London dispersion forces make A-A ≈ B-B ≈ A-B, satisfying the ideal condition. Option C (H-bonding) is wrong — neither compound is a H-bond donor; option D is a distractor since molar mass similarity is a coincidence, not the cause.
Q22Ideal and Non Ideal Solutions
When two liquids showing positive deviation from Raoult's Law are mixed, the enthalpy of mixing (ΔH_mix) is
Not quite — the answer is C.
Positive deviation: A-B interactions weaker than A-A and B-B → energy must be supplied to break stronger like-molecule interactions → ΔH_mix > 0 (endothermic). ΔH_mix = 0 only for ideal solutions; negative ΔH_mix indicates negative deviation (exothermic mixing).
Q23Types of Solutions
Which of the following is an example of solid in liquid solution?
Not quite — the answer is C.
Salt (solid solute) dissolves in water (liquid solvent) forming a solid-in-liquid solution; hydrogen in palladium is gas-in-solid, fog and mist are liquid-in-gas dispersions.
Q24Types of Solutions
Which of the following is an example of gas in liquid solution?
Not quite — the answer is B.
Oxygen (gas) dissolves in water (liquid) — essential for aquatic life — forming a gas-in-liquid solution; brass and steel are solid-in-solid alloys, iodine in CCl₄ is solid-in-liquid.
ELITE question · AIR under 50 level
This chapter has 249 ELITE questions for students aiming at the very top. They are only in the app.
Unlock ELITE questions in the appKey Solution Concepts
Quick revision: most questions in this chapter test these facts.
| Concept | Key Fact |
|---|---|
| Raoult's law | P = P°·x (for ideal solutions); positive deviation → weaker interactions; negative → stronger |
| Colligative properties | Depend on number of solute particles, not nature: RLVP, ΔTb, ΔTf, π |
| ΔTb | ΔTb = Kb·m·i; Kb = ebullioscopic constant; i = van't Hoff factor |
| ΔTf | ΔTf = Kf·m·i; Kf = cryoscopic constant; used for molecular mass determination |
| Osmotic pressure | π = iCRT; reverse osmosis: P > π forces solvent through membrane |
| van't Hoff factor (i) | i > 1 for electrolytes (dissociation); i < 1 for association |
What the app covers in this chapter
552 questions in total, each with a detailed explanation.
| Important PYQ Mixed Concepts | 140 |
| Grand Test | 59 |
| Mixed Revision | 56 |
| Reverse Osmosis and Applications | 41 |
| Types of Solutions | 40 |
| Vapour Pressure of Liquid Solutions | 40 |
| Colligative Properties | 40 |
| Expressing Concentration of Solutions | 39 |
| Solubility | 39 |
| Abnormal Molar Mass | 38 |
| Ideal and Non Ideal Solutions | 20 |
Questions students ask
Is Solutions important for NEET?
Yes — it is a high-weightage Physical Chemistry chapter. Colligative properties, Raoult's law and van't Hoff factor calculations appear every year.
Which topics should I revise first?
Master all four colligative properties with formulas, Raoult's law with positive/negative deviations, van't Hoff factor for electrolytes and non-electrolytes, and osmotic pressure calculations.
How many questions from this chapter are on RankUp?
The RankUp app has 552 questions on Solutions, including 249 ELITE questions. Every question has a detailed explanation.
