What does Solutions cover for NEET Chemistry?

9 lessons: Colligative Properties, Concentration Units, Depression Freezing Point, Elevation Boiling Point, Ideal Non-Ideal Solutions, Osmotic Pressure, Relative Lowering Vapour Pressure, Van 't Hoff Factor and Vapour Pressure Raoult.

How often has Solutions come up in NEET past papers?

Our set of verified past papers has 11 questions from this unit, from NEET 2020, 2021, 2022, 2024, 2025 and 2026. Each is answered against the official NTA key.

Is the Solutions material free?

Yes. All 9 lessons and 72 practice questions are free, with no login needed.

Solutions

9 lessons

Topic index in NCERT order

9 of 9 lessons by the NCERT chapter they teach from, in book order. The page is the first printed page of your NCERT book the lesson cites; PYQs are the past NEET questions on that topic.

Class 12 Chemistry, Chapter 1

Concentration Unitsp. 42 PYQs
Vapour Pressure Raoultp. 102 PYQs
Ideal Non-Ideal Solutionsp. 133 PYQs
Colligative Propertiesp. 150 PYQs
Relative Lowering Vapour Pressurep. 160 PYQs
Elevation Boiling Pointp. 171 PYQ
Depression Freezing Pointp. 181 PYQ
Osmotic Pressurep. 222 PYQs
Van 't Hoff Factorp. 240 PYQs

Colligative Properties

8 MCQs7 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Concentration Units

8 MCQs2 PYQs6 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Depression Freezing Point

8 MCQs1 PYQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Elevation Boiling Point

8 MCQs1 PYQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Ideal Non-Ideal Solutions

8 MCQs3 PYQs1 revision cardWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Osmotic Pressure

8 MCQs2 PYQs6 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Relative Lowering Vapour Pressure

8 MCQs4 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Van 't Hoff Factor

8 MCQs7 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Vapour Pressure Raoult

8 MCQs2 PYQs4 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Past-paper questions from this unit

11 questions from NEET 2020, 2021, 2022, 2024, 2025, 2026. Answers verified against NTA official keys.

By year in our set: 2020 (2) · 2021 (2) · 2022 (1) · 2024 (1) · 2025 (3) · 2026 (2)

Lesson: Ideal Non-Ideal Solutions

NEET 2026

Assertion A: For an ideal solution formed by mixing liquids P and Q, Δ_mix H = 0 and Δ_mix V = 0. Reason R: No interactions occur between P and Q. In the light of the above statements, choose the most appropriate answer from the options given below.

1Both A and R are correct and R is the correct explanation of A

2Both A and R are correct but R is NOT the correct explanation of A

3A is correct but R is not correct

4A is not correct but R is correct

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Vapour Pressure Raoult

NEET 2026

Consider the following statements about the solutions formed by mixing two liquids. A. An ideal solution thus formed obeys Raoult's law throughout the composition range. B. Mixture of chloroform and acetone shows negative deviation from Raoult's law. C. Mixture of aniline and phenol shows positive deviation from Raoult's law.

1A and B only

2B and C only

3A only

4A and C only

NTA Answer: Option 1(final)

Report an error · Every fix is public: corrections log

Lesson: Elevation Boiling Point

NEET 2025

Which of the following aqueous solution will exhibit highest boiling point?

10.015M C6H12O6

20.01M Urea

30.01M KNO3

40.01M Na2SO4

NTA Answer: Option 4(final)

Report an error · Every fix is public: corrections log

Lesson: Concentration Units

NEET 2025

Match List-I with List-II List-I List-II (Example) (Type of Solution) A. Humidity I. Solid in solid B. Alloys II. Liquid in gas C. Amalgams III. Solid in gas D. Smoke IV. Liquid in solid Choose the correct answer from the options given below:

1A-III, B-II, C-I, D-IV

2A-II, B-IV, C-I,D-III

3A-II, B-I, C-IV, D-III

4A-III, B-I, C-IV, D-II

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Ideal Non-Ideal Solutions

NEET 2025

5 moles of liquid X and 10 moles of liquid Y make a solution having a vapour pressure of 70 torr. The vapour pressures of pure X and Y are 63 torr and 78 torr respectively. Which of the following is true regarding the described solution?

1The solution has volume greater than the sum of individual volumes.

2The solution shows positive deviation.

3The solution shows negative deviation.

4The solution is ideal.

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Osmotic Pressure

NEET 2024Revised key

The plot of osmotic pressure (Π) vs concentration (mol L⁻¹) for a solution gives a straight line with slope 25.73 L bar mol⁻¹. The temperature at which the osmotic pressure measurement is done is (Use R = 0.083 L bar mol⁻¹ K⁻¹)

137°C

2310°C

325.73°C

412.05°C

NTA Answer: Option 1(revised_final)

Report an error · Every fix is public: corrections log

Lesson: Concentration Units

NEET 2022

In one molal solution that contains 0.5 mole of a solute, there is

11000 g of solvent

2500 mL of solvent

3500 g of solvent

4100 mL of solvent

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Osmotic Pressure

NEET 2021

The following solutions were prepared by dissolving 10 g of glucose (C₆H₁₂O₆) in 250 ml of water (P₁), 10 g of urea (CH₄N₂O) in 250 ml of water (P₂) and 10 g of sucrose (C₁₂H₂₂O₁₁) in 250 ml of water (P₃). The right option for the decreasing order of osmotic pressure of these solutions is :

1P₃ > P₁ > P₂

2P₂ > P₁ > P₃

3P₁ > P₂ > P₃

4P₂ > P₃ > P₁

NTA Answer: Option 2(final)

Report an error · Every fix is public: corrections log

Lesson: Vapour Pressure Raoult

NEET 2021

The correct option for the value of vapour pressure of a solution at 45°C with benzene to octane in molar ratio 3 : 2 is : [At 45°C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas]

1350 mm of Hg

2160 mm of Hg

3168 mm of Hg

4336 mm of Hg

NTA Answer: Option 4(final)

Report an error · Every fix is public: corrections log

Lesson: Depression Freezing Point

NEET 2020

The freezing point depression constant (Kf ) of benzene is 5.12 K kg mol⁻¹. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is (rounded off upto two decimal places) :

10.60 K

20.20 K

30.80 K

40.40 K

NTA Answer: Option 4(final)

Report an error · Every fix is public: corrections log

Lesson: Ideal Non-Ideal Solutions

NEET 2020

The mixture which shows positive deviation from Raoult’s law is :

1Chloroethane+Bromoethane

2Ethanol+Acetone

3Benzene+Toluene

4Acetone+Chloroform

NTA Answer: Option 2(final)

Report an error · Every fix is public: corrections log

Exam traps and common mistakes in this unit

Lesson: Colligative Properties

Trap

Forgetting Van't Hoff factor

Category: Similar Terms

Student uses non-electrolyte colligative formula for ionic compound. NaCl: i ≈ 2; CaCl₂: i ≈ 3.

When it triggers

Question gives an ionic compound (NaCl, CaCl₂, K₂SO₄) and asks for colligative property.

How to avoid

For electrolytes, multiply colligative formula by Van't Hoff factor i. NaCl → Na⁺ + Cl⁻ (i=2). CaCl₂ → Ca²⁺ + 2Cl⁻ (i=3). K₂SO₄ → 2K⁺ + SO₄²⁻ (i=3).

Lesson: Vapour Pressure Raoult

Trap

Mole vs mass fraction

Category: Similar Terms

Student uses mass fraction (w₁/total mass) where mole fraction (n₁/total moles) is required.

When it triggers

Question gives masses or molar masses and asks about Raoult's law or vapor pressure.

How to avoid

Raoult's law uses MOLE fractions, not mass fractions. Convert mass to moles first using molar mass.

Lesson: Colligative Properties

Mistake

Forgets Van't Hoff factor i for ionic compounds in colligative formulas.

Root cause: formula misuse

Correction

For NaCl i ≈ 2, CaCl₂ i ≈ 3, K₂SO₄ i ≈ 3. Multiply colligative formulas by i.

Lesson: Vapour Pressure Raoult

Mistake

Substitutes mass fraction for mole fraction in Raoult's law.

Root cause: formula misuse

Correction

Convert mass to moles first using molar mass. Raoult uses MOLE fractions.

Formulas in this unit

Lesson: Concentration Units

Molality

m = n / m_{solv}

Molal concentration: moles of solute per kg of solvent. Temperature-independent.

Symbol	Quantity	SI Unit
m	molality	mol/kg
n	moles solute	mol

Valid when

Mass of SOLVENT (not solution)

Lesson: Concentration Units

Molarity

M = n / V

Molar concentration: moles of solute per litre of solution.

Symbol	Quantity	SI Unit
M	molarity	mol/L
n	moles solute	mol
V	solution volume	L

Valid when

Volume of SOLUTION not solvent
Temperature dependent (volume changes with T)

Lesson: Depression Freezing Point

Freezing-point depression

Δ T_{f} = K_{f} m

Solute lowers freezing point. K_f is cryoscopic constant of solvent (water: 1.86 K kg/mol). Used for molar mass determination.

Symbol	Quantity	SI Unit
ΔT_f	FP depression	K
K_f	cryoscopic constant	K kg/mol
m	molality	mol/kg

Valid when

Dilute solution
Non-electrolyte (else multiply by i)

Lesson: Elevation Boiling Point

Boiling-point elevation

Δ T_{b} = K_{b} m

Solute raises boiling point. K_b is ebullioscopic constant of solvent (water: 0.52 K kg/mol).

Symbol	Quantity	SI Unit
ΔT_b	BP elevation	K
K_b	ebullioscopic constant	K kg/mol
m	molality	mol/kg

Valid when

Dilute solution
Non-electrolyte

Lesson: Osmotic Pressure

Osmotic pressure

π = C R T

Pressure required to prevent osmosis. C in mol/L; T in K. Used for high-molar-mass biomolecules.

Symbol	Quantity	SI Unit
π	osmotic pressure	Pa
C	molarity	mol/L
R	gas constant	J/mol/K
T	temp	K

Valid when

Dilute solution
Semipermeable membrane separating pure solvent from solution

Lesson: Relative Lowering Vapour Pressure

Relative lowering of VP

\frac{p ^{\circ} - p}{p ^{\circ}} = x_{solute}

For non-volatile solute: relative lowering of VP equals mole fraction of solute.

Symbol	Quantity	SI Unit
p	solution vp	Pa
p°	pure solvent vp	Pa
x_solute	mole fraction	-

Valid when

Non-volatile solute
Dilute solution
Non-electrolyte (else use i)

Lesson: Van 't Hoff Factor

Van't Hoff factor

i = \frac{observed}{theoretical}

Correction factor for electrolytes. NaCl: i≈2; CaCl₂: i≈3. Multiply colligative formula by i.

Symbol	Quantity	SI Unit
i	Van't Hoff factor	-

Valid when

Electrolyte solution
Account for ion-pair association/dissociation

Lesson: Vapour Pressure Raoult

Raoult's law

p = p_{1}^{\circ} x_{1} + p_{2}^{\circ} x_{2}

Total vapor pressure of ideal solution = sum of mole-fraction-weighted vapor pressures of components.

Symbol	Quantity	SI Unit
p	total vapor pressure	Pa
p_i°	pure component vp	Pa
x_i	mole fraction	-

Valid when

Ideal solution
Both volatile

NEET question patterns in this unit

Lesson: Colligative Properties

Calculate ΔT_f or ΔT_b given molality. Or determine molar mass from observed colligative property.

Multi StepMedium

Common distractors

forgets i factor electrolytes

Uses non-electrolyte formula for ionic solute

Lesson: Ideal Non-Ideal Solutions

Find total VP of ideal solution from mole fractions and pure-component VPs.

Direct ApplicationEasy

Common distractors

uses mass fractions not mole

Substitutes mass fraction for x

Lesson: Osmotic Pressure

π = CRT. Find molar mass of solute from observed osmotic pressure.

Direct ApplicationEasy

Common distractors

forgets conversion of units

Mixes Pa with atm; L with m^3

Questions about this unit

What does Solutions cover for NEET Chemistry?: 9 lessons: Colligative Properties, Concentration Units, Depression Freezing Point, Elevation Boiling Point, Ideal Non-Ideal Solutions, Osmotic Pressure, Relative Lowering Vapour Pressure, Van 't Hoff Factor and Vapour Pressure Raoult.
How often has Solutions come up in NEET past papers?: Our set of verified past papers has 11 questions from this unit, from NEET 2020, 2021, 2022, 2024, 2025 and 2026. Each is answered against the official NTA key.
Is the Solutions material free?: Yes. All 9 lessons and 72 practice questions are free, with no login needed.