Free MHT-CET Solutions Quiz | Important MCQs with Answers

📌 Question 1

Which concentration term is temperature dependent?

AMolality

BMole fraction

CMolarity

DMass percentage

✅ Right Answer: (C) Molarity
Molarity = moles/volume(L); volume changes with temperature → temperature dependent.

---

📌 Question 2

Molality of 4.0 g NaOH (40 g/mol) in 250 g water?

A0.1 m

B0.4 m

C0.25 m

D0.05 m

✅ Right Answer: (B) 0.4 m
Moles = 4/40 = 0.1; mass solvent = 0.25 kg → molality = 0.1/0.25 = 0.4 m.

---

📌 Question 3

Which is INCORRECT for an ideal solution?

✔ ΔH_mix = 0

✔ ΔV_mix = 0

✔ Obey Raoult's law

✘ Solute-solvent interactions stronger than pure components

✅ Right Answer: (D) Solute-solvent interactions stronger than pure components
Ideal solutions have similar interactions; stronger interactions cause negative deviation.

---

📌 Question 4

Best colligative property to find molar mass of polymer?

A) Lowering of V.P.

B) Elevation in B.P.

C) Depression in F.P.

D) Osmotic pressure

✅ Right Answer: (D) Osmotic pressure
Osmotic pressure method is highly sensitive for macromolecules.

---

📌 Question 5

Van’t Hoff factor (i) for dissociation of solute is:

A) i = 1

B) i > 1

C) i < 1

D) i = 0

✅ Right Answer: (B) i > 1
Dissociation increases number of particles → i > 1.

---

📌 Question 6

Highest boiling point among 0.1 m solutions? (complete dissociation)

A) NaCl

B) Glucose

C) CaCl₂

D) Urea

✅ Right Answer: (C) CaCl₂
ΔTb ∝ i×m ; CaCl₂ → i≈3 (max particles).

---

📌 Question 7

Osmotic pressure (π) is directly proportional to:

A) Temperature only

B) Molar concentration & absolute temperature

C) Volume of solution

D) Molar mass

✅ Right Answer: (B) Molar concentration & absolute temperature
π = CRT

---

📌 Question 8

Relative lowering of vapour pressure = 0.02, mole fraction of solute?

A) 0.98

B) 0.02

C) 0.01

D) 0.04

✅ Right Answer: (B) 0.02
ΔP/P° = x_solute (Raoult's law for dilute).

---

📌 Question 9

Which pair shows positive deviation from Raoult's law?

A) Acetone + Chloroform

B) Ethanol + Water

C) Benzene + Toluene

D) CS₂ + Acetone

✅ Right Answer: (D) CS₂ + Acetone
Weaker A-B interactions → positive deviation.

---

📌 Question 10

Freezing point of 0.2 molal non-electrolyte? (Kf = 1.86 K kg/mol)

A) -0.372°C

B) -0.186°C

C) 0.372°C

D) 0.0°C

✅ Right Answer: (A) -0.372°C
ΔTf = 1.86×0.2 = 0.372°C depression → FP = -0.372°C.

---

📌 Question 11

Van’t Hoff factor for K₂SO₄ (complete dissociation) is:

A) 1

B) 2

C) 3

D) 4

✅ Right Answer: (C) 3
K₂SO₄ → 2K⁺ + SO₄²⁻ → total 3 ions.

---

📌 Question 12

Correct statement about azeotropes?

A) Constant boiling mixture

B) Cannot be separated by fractional distillation

C) Same composition in liquid & vapour

D) All of these

✅ Right Answer: (D) All of these
Azeotropes behave like pure compounds with fixed composition.

---

📌 Question 13

Ebullioscopic constant (Kb) depends on:

A) Nature of solute

B) Nature of solvent

C) Molarity

D) Pressure

✅ Right Answer: (B) Nature of solvent
Kb = RTb²/(1000×ΔHvap) → solvent property.

---

📌 Question 14

0.5 g ethylene glycol (M=62) in 100g water, ΔTf? (Kf=1.86)

A) 0.15 K

B) 0.30 K

C) 0.12 K

D) 0.45 K

✅ Right Answer: (A) 0.15 K
moles = 0.5/62≈0.0080645; m=0.080645; ΔTf =1.86×0.0806≈0.15K.

---

📌 Question 15

Which is NOT a colligative property?

A) Osmotic pressure

B) Vapour pressure lowering

C) Refractive index

D) Freezing point depression

✅ Right Answer: (C) Refractive index
Colligative properties depend only on number of solute particles.

---

📌 Question 16

10 g solute in 100g benzene, BP 81.2°C (pure benzene 80.1°C), Kb=2.53. Molar mass?

A) 115 g/mol

B) 230 g/mol

C) 150 g/mol

D) 180 g/mol

✅ Right Answer: (B) 230 g/mol
ΔTb=1.1; m=1.1/2.53=0.4348; moles solute=0.04348; M=10/0.04348≈230.

---

📌 Question 17

Highest osmotic pressure at 300K? (0.1M each)

A) AlCl₃

B) BaCl₂

C) NaCl

D) Urea

✅ Right Answer: (A) AlCl₃
π = iCRT, AlCl₃ → i≈4 → maximum.

---

📌 Question 18

Negative deviation from Raoult's law occurs when:

A) A-B interactions weaker

B) A-B interactions stronger

C) ΔHmix > 0

D) Volume increases

✅ Right Answer: (B) A-B interactions stronger
Stronger cross interactions reduce vapour pressure → negative deviation.

---

📌 Question 19

Unit of cryoscopic constant (Kf) is:

A) K kg mol⁻¹

B) K mol kg⁻¹

C) mol kg⁻¹ K⁻¹

D) K⁻¹ kg mol⁻¹

✅ Right Answer: (A) K kg mol⁻¹
Kf has units: Kelvin · kg / mol.

---

📌 Question 20

Condition for ideal solution:

A) ΔHmix = 0, ΔVmix = 0

B) ΔSmix = 0

C) ΔGmix = 0

D) ΔHmix > 0

✅ Right Answer: (A) ΔHmix = 0, ΔVmix = 0
Ideal solutions: no heat or volume change on mixing.

---

📚 Lakshya MHT-CET · Solutions Chapter Practice · Click on each "Show Answer" to check. All rights reserved.