Question

Highest limiting conductance at 298 K is:

• A. \( \text{Ca}^{2+} \)
• B. \( \text{Cs}^+ \)
• C. \( \text{K}^+ \)
• D. \( \text{Na}^+ \)

Hint:

Remember that higher ionic radii generally lead to higher mobility and thus higher conductivity, which is why Cs⁺ has the highest conductance.

Answer 1

The Correct Option is B

The limiting molar conductivity \(\Lambda_{\text{m}}^{\infty}\) is the conductance of an electrolyte when it is dissociated completely. Among all the ions, Cs⁺ (Cesium ion) has the highest limiting molar conductivity at 298 K due to its larger ionic radius, which allows it to move more freely through a solution. The ionic radius is crucial for determining conductivity because a larger ion moves more easily through the solution, contributing to higher conductivity. Thus, the correct answer is Cs⁺.