Question:medium

Which of the following expressions correctly represents molar conductivity?

Show Hint

Molar conductivity decreases with increasing concentration due to ion-pair formation but increases with dilution as ions move more freely in the solution.
Updated On: Jan 13, 2026
  • \( \Lambda_m = \frac{K}{C} \)
  • \( \Lambda_m = \frac{KA}{l} \)
  • \( \Lambda_m = K V \)
  • \( \text{All of these} \)
Show Solution

The Correct Option is D

Solution and Explanation

Molar conductivity (\( \Lambda_m \)) is influenced by factors including conductivity (\( K \)), concentration (\( C \)), and solution geometry. Different derivations clarify this:

1. Conductivity and Concentration: The basic definition is \( \Lambda_m = \frac{K}{C} \). This indicates that at constant conductivity, molar conductivity is inversely proportional to concentration.

2. Geometry and Conductance: Conductivity (\( K \)) relates to conductance (\( G \)) via \( G = \frac{K \cdot A}{l} \), where \( A \) is cross-sectional area and \( l \) is electrode distance. Substituting this into molar conductivity yields \( \Lambda_m = \frac{KA}{l} \), highlighting the cell's geometric impact.

3. Volume Dependence: For a solution with 1 mole of electrolyte, molar conductivity is \( \Lambda_m = K V \), where \( V \) is the volume containing 1 mole of solute. This shows molar conductivity's dependence on dilution.

Analysis: The expressions \( \Lambda_m = \frac{K}{C} \), \( \Lambda_m = \frac{KA}{l} \), and \( \Lambda_m = K V \) are all valid representations of molar conductivity, each derived from a distinct perspective.

Final Answer: \[ \boxed{\text{All of these}} \]

Was this answer helpful?
0