Take timed practice tests on Solutions and Colligative Properties for JEE Main and JEE Advanced with session-wise drills, score review, and explanation-led revision.
Six 20-question timed sessions plus a 60-question chapter module. Each item is original and reframed for copyright safety.
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1. A solution in which the solvent is water is called:
Explanation: An aqueous solution has water as the solvent. Non-aqueous solutions use other solvents (e.g., benzene, ethanol).
2. Molarity is defined as:
Explanation: Molarity (M) = moles of solute / volume of solution in litres. It is temperature-dependent because volume changes with temperature.
3. Molality (m) is temperature-independent because:
Explanation: Molality = moles of solute / mass of solvent in kg. Mass does not change with temperature, so molality is temperature-independent.
4. Raoult's law states that for a volatile solute, the partial pressure of the solvent over the solution is:
Explanation: Raoult's law: p_A = x_A × p°_A. The partial pressure of solvent A equals its mole fraction times its pure vapour pressure.
5. Colligative properties depend on:
Explanation: Colligative properties (vapour pressure lowering, boiling point elevation, freezing point depression, osmotic pressure) depend only on the number (concentration) of dissolved particles, not on their chemical identity.
6. ΔTb = Kb × m. If Kb of water = 0.52 K kg mol⁻¹ and 1 mol glucose is dissolved in 1 kg water, ΔTb is:
Explanation: ΔTb = Kb × m = 0.52 × 1 = 0.52 K. The new boiling point = 100 + 0.52 = 100.52°C.
7. Kf for water is 1.86 K kg mol⁻¹. For 0.1 m NaCl (i ≈ 2), ΔTf is:
Explanation: ΔTf = i × Kf × m = 2 × 1.86 × 0.1 = 0.372 K. NaCl dissociates into Na⁺ and Cl⁻ → van't Hoff factor i = 2.
8. The osmotic pressure of a solution is given by:
Explanation: Osmotic pressure: π = CRT = MRT, where C = M = molar concentration, R = gas constant, T = temperature in K. Analogous to the ideal gas equation.
9. For acetic acid in benzene, dimerisation occurs. The van't Hoff factor i is:
Explanation: Dimerisation decreases the number of solute particles. If all molecules dimerise: i = 0.5. Generally for association i 1.
10. Henry's law states that the solubility of a gas in a liquid is:
Explanation: Henry's law: p = KH × x (or C = KH' × p). The concentration of a dissolved gas is proportional to its partial pressure. Used to explain carbonation, oxygen solubility in blood.
11. An aqueous solution of NaCl freezes at −0.744°C. Kf = 1.86 K kg mol⁻¹. The molality of NaCl is:
Explanation: ΔTf = i×Kf×m → 0.744 = 2×1.86×m → m = 0.744/3.72 = 0.2 mol/kg.
12. For a non-ideal solution showing positive deviation from Raoult's law:
Explanation: Positive deviation: A-B forces 0 (endothermic). Example: ethanol + water (partially), acetone + CS₂.
13. The van't Hoff factor for a dilute glucose solution is:
Explanation: Glucose is a non-electrolyte and does not dissociate or associate in dilute aqueous solution. i = 1.
14. Reverse osmosis is applied pressure:
Explanation: In reverse osmosis, external pressure > osmotic pressure is applied to the solution side, forcing solvent (water) to flow from concentrated to dilute side through a semipermeable membrane. Used in water purification.
15. If 5.85 g of NaCl (M=58.5) is dissolved in 500 g water, the molality is:
Explanation: Moles NaCl = 5.85/58.5 = 0.1 mol. Molality = 0.1 mol / 0.5 kg = 0.2 mol/kg.