AIIMS2017Chemistry-Solutions

AIIMS 2017 Chemistry Van’t Hoff factor MCQ Question

Type: MCQ-conceptual-Medium-Class 12

We have three aqueous solutions of NaCl\text{NaCl} labelled as (A), (B) and (C) with concentrations of 0.1 M0.1\text{ M}, 0.01 M0.01\text{ M} and 0.001 M0.001\text{ M}, respectively. The value of the van 't Hoff factor (ii) of these solutions will be in the order:

A

iA<iB<iCi_{\text{A}} < i_{\text{B}} < i_{\text{C}}

B

iA>iB>iCi_{\text{A}} > i_{\text{B}} > i_{\text{C}}

C

iA=iB=iCi_{\text{A}} = i_{\text{B}} = i_{\text{C}}

D

iA<iB>iCi_{\text{A}} < i_{\text{B}} > i_{\text{C}}

Correct Answer

Option C

Detailed Explanation

The Van’t Hoff factor (i) represents the number of particles into which a solute dissociates in solution, and it is primarily determined by the nature of the solute rather than its concentration. For example, NaCl dissociates into two ions (Na⁺ and Cl⁻), giving it a Van’t Hoff factor of i = 2, regardless of how concentrated the solution is. Options A, B, and D are not applicable as they do not provide relevant information or alternatives regarding the Van’t Hoff factor, which remains consistent for a given solute under similar conditions. Understanding this concept is crucial for predicting colligative properties, such as boiling point elevation and freezing point depression, which depend on the number of solute particles in solution.

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