NEET Chemistry: Colligative properties Practice Questions
10 free multiple-choice questions on Colligative properties (Solutions) for NEET Chemistry, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. If the vapor pressure of a solution is lower than that of the pure solvent, which colligative property is being described?
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Correct answer: D — Relative Lowering of Vapor Pressure
When a non-volatile solute is added to a solvent, it lowers the vapor pressure above the liquid surface. This is described by the concept of Relative Lowering of Vapor Pressure.
Q2. The presence of an electrolyte (like NaCl) in water causes the freezing point to be depressed. This depression is related to the number of particles formed when the solute dissolves. This concept is governed by which factor?
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Correct answer: C — van't Hoff factor
The depression of freezing point is related to the total number of solute particles. This relationship is quantified by the van't Hoff factor (i), which accounts for dissociation.
Q3. In a solution formed by two volatile liquids, A and B, the vapor pressure of the resulting solution is lower than that of the pure liquid A. This phenomenon is described by which principle of colligative properties?
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Correct answer: B — Raoult's Law
Lowering of vapor pressure due to the presence of a non-volatile solute is directly described by Raoult's Law. Raoult's Law states that the partial vapor pressure of a solvent above a solution is equal to the mole fraction of that solvent in the solution multiplied by the vapor pressure of the pure solvent.
Q4. If a solution exhibits a relative lowering of vapor pressure of 20%, what is the mole fraction of the solvent in the solution?
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Correct answer: D — 0.80
If the vapor pressure is lowered by 20%, it means the mole fraction of the solvent is 1 - 0.20 = 0.80.
Q5. The depression in the freezing point of a solution is directly proportional to the molality of the solute. This statement is fundamentally related to which concept?
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Correct answer: B — Colligative Properties
Freezing point depression is a colligative property, meaning it depends on the number of solute particles present in a given amount of solvent, which is directly proportional to molality (or mole fraction).
Q6. Which of the following colligative properties depends solely on the number of solute particles present in a given amount of solvent?
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Correct answer: D — All of the above
Colligative properties (like vapor pressure lowering and boiling point elevation) are directly proportional to the concentration of solute particles, making them dependent only on the number of solute particles, not their nature. Osmotic pressure is also based on particle concentration.
Q7. Which of the following statements correctly describes vapor pressure lowering in a solution?
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Correct answer: B — It is caused by the reduced escaping tendency of the solvent molecules.
Vapor pressure lowering occurs because the solute particles occupy some surface area of the liquid, reducing the number of solvent molecules able to move to the surface and exert vapor pressure.
Q8. If the concentration of a solution is increased, the magnitude of the freezing point depression will:
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Correct answer: C — Increase
Freezing point depression is directly proportional to the molality/concentration of the solute. Therefore, increasing the concentration increases the depression magnitude.
Q9. The osmotic pressure exerted by a solution is a colligative property. This pressure arises due to the tendency of the solvent to flow across a semi-permeable membrane. This property is related to which fundamental concept?
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Correct answer: B — Concentration gradient
Osmotic pressure is driven by the difference in concentration (concentration gradient) across the semi-permeable membrane, causing the solvent to move from the region of lower concentration to higher concentration.
Q10. Which of the following properties is dependent only on the number of solute particles present in a solution, and not on the nature of the solute?
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Correct answer: D — All of the above
Colligative properties (like boiling point elevation, freezing point depression, and osmotic pressure) depend solely on the concentration (number of solute particles) of the solution, not the identity of the solute particles.
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