Question

When \( 0.1 \, mol \, L^{-1} \) of KCl was filled in a Conductivity cell the resistance was 80 ohms at 298 K. Conductivity of \( 0.1 \, M \) KCl at 298 K is \( 1.29 \, S \, m^{-1} \). The same cell when filled with an unknown electrolyte of concentration \( 0.025 \, M \), had a resistance of 92 ohms. What is the Molar conductivity of the electrolyte at the given concentration?

• A. \( 220.6 \, S \, cm^2 \, mol^{-1} \)
• B. \( 0.2206 \, S \, cm^2 \, mol^{-1} \)
• C. \( 448 \, S \, cm^2 \, mol^{-1} \)
• D. \( 0.449 \, S \, cm^2 \, mol^{-1} \)

Hint:

First calculate the cell constant using standard KCl solution, then use it to find conductivity of the unknown solution and finally apply \( \Lambda_m = \frac{\kappa \times 1000}{C} \).

Answer 1

The Correct Option is C