JEE Main 2026 Jan 28 Shift 2, Chemistry Q23: Colligative Properties

JEE Main2026Jan 28, Shift 2Chemistry

For strong electrolyte $Λ_{m}$ increases slowly with dilution and can be represented by the equation $Λ_{m} = Λ_{m}^{\circ} - A c$ .

Molar conductivity values of the solutions of strong electrolyte AB at 18 $^{\circ}$ C are given below :

The value of constant A based on the above data [in S cm $^{2}$ mol $^{- 1}$ /(mol/L) $^{1/2}$ ] unit is _____ .

Your answer

Solution

Apply $Λ_{m} = Λ_{m}^{\circ} - A c$ at two concentrations and subtract to eliminate $Λ_{m}^{\circ}$ .

At $c = 0.04$ : $96.1 = Λ_{m}^{\circ} - A (0.2)$ ... (1)

At $c = 0.09$ : $95.7 = Λ_{m}^{\circ} - A (0.3)$ ... (2)

(1) - (2): $0.4 = 0.1 A \Rightarrow A = 4$ .

Concept behind this question

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