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Chemistry · PYQ NEET UG 2026
हिन्दीFor a salt \( \text{XY} \), which is a strong electrolyte, the plot of \( \Lambda_m \) versus \( \sqrt{c} \) has a slope of \( -90.0 \text{ S cm}^2 \text{ mol}^{-3/2} \text{ L}^{1/2} \) at \( 298\text{ K} \). At \( 0.01\text{ M} \) concentration of \( \text{XY} \), the value of \( \Lambda_m \) is \( 145.0 \text{ S cm}^2 \text{ mol}^{-1} \). The limiting molar conductivity of \( \text{Y}^- \) ion (\( \lambda^0_{\text{Y}^-} \), in \( \text{S cm}^2 \text{ mol}^{-1} \)) at \( 298\text{ K} \) will be (Given: \( \lambda^0_{\text{X}^+} = 74.0 \text{ S cm}^2 \text{ mol}^{-1} \))
Correct answer · Option 3
\( 90.0 \)
Explanation
Using Debye-Huckel-Onsager equation: \( \Lambda_m = \Lambda^0_m - A\sqrt{c} \). \( \Lambda^0_m = 145 + 90 \times \sqrt{0.01} = 154 \). Then \( \lambda^0_{\text{Y}^-} = 154 - 74 = 90\text{ S cm}^2 \text{ mol}^{-1} \).
