Chemistry Question from JEE Main 2023 · 29 January, Shift 1

The following figure shows the dependence of molar conductance of two electrolytes on concentration, where $\Lambda_m^\circ$ is the limiting molar conductivity.

The figure shows: a plot whose vertical axis is labelled $\Lambda_m / \text{S cm}^2\,\text{mol}^{-1}$ and whose horizontal axis is labelled $\sqrt{c}\ (\text{mol/L})^{1/2}$. Two curves are drawn on it. The curve labelled A starts very high, close to the $\Lambda_m$ axis, drops steeply as $\sqrt{c}$ increases and then flattens into an almost horizontal tail at larger $\sqrt{c}$; it never becomes a straight line, so it cannot be extrapolated back to $\sqrt{c} = 0$. The curve labelled B is very nearly a straight line: it starts from a finite intercept on the $\Lambda_m$ axis and falls slowly and almost linearly as $\sqrt{c}$ increases. The two curves cross near the left-hand edge of the plot, so A lies above B at very small $\sqrt{c}$ and below B afterwards.

The number of incorrect statements from the following is _____.

(A) $\Lambda_m^\circ$ for electrolyte A is obtained by extrapolation.

(B) For electrolyte B, the $\Lambda_m$ versus $\sqrt{c}$ graph is a straight line with intercept equal to $\Lambda_m^\circ$.

(C) At infinite dilution, the value of the degree of dissociation approaches zero for electrolyte B.

(D) $\Lambda_m^\circ$ for any electrolyte A or B can be calculated using $\lambda^\circ$ for individual ions.