Freezing point of solution is less than that of pure solvent, which of the following statements are correct ?
(A) Vapour pressure of solution is less than that of pure solvent
(B) Vapour pressure of solution is greater than that of pure solvent
(C) Only solvent molecules will freeze
(D) Only solute molecules will freeze
(A) Vapour pressure of solution is less than that of pure solvent
(B) Vapour pressure of solution is greater than that of pure solvent
(C) Only solvent molecules will freeze
(D) Only solute molecules will freeze
A & B only
A & C only
C & D only
A, B & D only
The Correct Option is B
Solution and Explanation
The freezing point denotes the temperature where a substance's solid and liquid phases coexist harmoniously. Consequently, at this freezing point, the vapor pressure of the solid matches that of the liquid's vapor phase.
Upon introducing a non-volatile solute to the solvent, Raoult's law dictates that the solution's vapor pressure declines. Consequently, at lower temperatures, the solution's vapor pressure aligns with that of the pure solvent. As a result of this reduction in vapor pressure, the freezing point decreases, a phenomenon termed "depression in freezing point."
During this depression in the freezing point, the solution's vapor pressure falls below that of the solvent. Subsequently, since the solution's vapor pressure coincides with the vapor pressure of the pure solvent, only the solvent molecules undergo solidification.
The Correct Option is (B): \(A \;\& \;C \;only \)
Top Questions on Colligative Properties
- We have three aqueous solutions of NaCl labelled as ‘A’, ‘B’ and ‘C’ with concentration 0.1 M, 0.01M & 0.001 M, respectively. The value of vant’ Haft factor (i) for these solutions will be in the order.
- JEE Main - 2024
- Chemistry
- Colligative Properties
- The correct order of boiling points of the given aqueous solutions is
- WBJEE - 2024
- Chemistry
- Colligative Properties
- Mass of glucose (\(C_6H_{12}O_6\)) required to be dissolved to prepare one litre of its solution which is isotonic with \(15 \, \text{g L}^{-1}\) solution of urea (\(NH_2CONH_2\)) is:
{Given:} Molar mass in \(\text{g mol}^{-1}\): \[ C : 12, \, H : 1, \, O : 16, \, N : 14 \]- NEET (UG) - 2024
- Chemistry
- Colligative Properties
- An artificial cell is made by encapsulating \(0.2 \, \text{M}\) glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a \(0.05 \, \text{M}\) solution of NaCl at 300 K is ______ \( \times 10^{-1} \, \text{bar} \). (Nearest Integer)
Given: \(R = 0.083 \, \text{L bar mol}^{-1} \text{K}^{-1}\)
Assume complete dissociation of NaCl.- JEE Main - 2024
- Chemistry
- Colligative Properties
- Consider the dissociation of the weak acid HX as given below:
\[\text{HX(aq)} \rightleftharpoons \text{H}^+(\text{aq}) + \text{X}^-(\text{aq}), \, K_a = 1.2 \times 10^{-5}\]
\([K_a: \text{dissociation constant}]\)
The osmotic pressure of \(0.03 \, \text{M}\) aqueous solution of HX at 300 K is ______ \( \times 10^{-2} \, \text{bar} \) (nearest integer).
Given: \(R = 0.083 \, \text{L bar mol}^{-1} \text{K}^{-1}\)- JEE Main - 2024
- Chemistry
- Colligative Properties
Questions Asked in JEE Main exam
- The area of the region enclosed by the parabolas \( y = x^2 - 5x \) and \( y = 7x - x^2 \) is _________.
- JEE Main - 2024
- Calculus
- If the function \(f(x) = \frac{\sin 3x + \alpha \sin x - \beta \cos 3x}{x^3},\) \(x \in \mathbb{R} \), is continuous at \( x = 0 \), then \( f(0) \) is equal to:
- JEE Main - 2024
- Continuity and differentiability
- The coordination geometry around the manganese in decacarbonyldimanganese(0) is
- JEE Main - 2024
- coordination compounds
- Given below are two statements:
Statement (I) : The NH2 group in Aniline is ortho and para directing and a powerful activating group.
Statement (II) : Aniline does not undergo Friedel- Craft’s reaction (alkylation and acylation). In the light of the above statements
Choose the most appropriate answer from the options given below :- JEE Main - 2024
- Aromaticity & chemistry of aromatic compounds
- A rectangular loop of length 2.5 m and width 2 m is placed at 60° to a magnetic field of 4 T. The loop is removed from the field in 10 sec. The average emf induced in the loop during this time is:
- JEE Main - 2024
- Electromagnetic induction
Concepts Used:
Colligative Properties
Colligative Property of any substance is entirely dependent on the ratio of the number of solute particles to the total number of solvent particles but does not depend on the nature of particles. There are four colligative properties: vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.
Examples of Colligative Properties
We can notice the colligative properties of arrangements by going through the accompanying examples:
- On the off chance that we add a spot of salt to a glass full of water, its freezing temperature is brought down impressively than its normal temperature. On the other hand, the boiling temperature is likewise increased and the arrangement will have a lower vapor pressure. There are also changes observed in its osmotic pressure.
- In the same way, if we add alcohol to water, the solution’s freezing point goes down below the normal temperature that is usually observed for either pure alcohol or water.
Types of Colligative Properties
- Freezing point depression: ΔTf =1000 x kf x m2 /(M2 x m1)
- Boiling point elevation: ΔTb = kb m
- Osmotic pressure: π = (n2/V) RT
- Relative lowering of vapor pressure: (Po - Ps)/Po