Question

The following graph is obtained for KCl solution at 300 K. What is \( \Lambda_m^0 \) (in S cm² mol\(^{-1}\)) of KCl? 

• A. \( 150 \)
• B. \( 90 \)
• C. \( 150 \times 90 \)
• D. \( 150 + 90 \)

Hint:

- The limiting molar conductivity (\( \Lambda_m^0 \)) is obtained by extrapolating the conductivity vs. concentration graph to zero concentration. - It follows Kohlrausch's Law, where the molar conductivity at infinite dilution is the sum of the individual ionic conductivities.

Answer 1

The Correct Option is D

Step 1: Understanding the given graph - The x-axis represents \( [\text{KCl}]^{1/2} \), and the y-axis represents \( \Lambda_m \) (molar conductivity). - The extrapolated value of \( \Lambda_m \) at infinite dilution (\( \Lambda_m^0 \)) corresponds to the y-intercept of the graph. 

Step 2: Identifying the intercept values - From the graph, the y-intercept has a contribution of 150 from one part and 90 from another. - Thus, the total value of \( \Lambda_m^0 \) is: \[ \Lambda_m^0 = 150 + 90 = 240 \text{ S cm}^2 \text{ mol}^{-1} \]