Chemistry class 12th Variation of conductivity

Variation of Conductivity and Molar Conductivity
1. Introduction
Conductivity (k) measures a solution's ability to conduct electricity, while molar conductivity
(Lambda_m) is the conductance of one mole of electrolyte in a given volume of solution. These
properties change with concentration.

2. Variation of Conductivity (k) with Concentration
Conductivity generally decreases as concentration decreases because there are fewer ions in solution
to carry current. - Strong electrolytes: Conductivity decreases slightly due to reduced ion
interaction. - Weak electrolytes: Conductivity decreases significantly due to limited ionization.

3. Variation of Molar Conductivity (Lambda_m) with Concentration
Molar conductivity increases with dilution because ions become more free to move: - Strong
electrolytes: Lambda_m increases slightly with dilution. - Weak electrolytes: Lambda_m increases
significantly as ionization increases.

4. Kohlrausch’s Law and its Applications
Kohlrausch's Law states that at infinite dilution, molar conductivity of an electrolyte is the sum
of its individual ion contributions: Lambda_m0 = lambda_0+ + lambda_0- Applications: -
Determining limiting molar conductivity. - Calculating ion mobility.

5. Graphical Representation
Graphs help visualize conductivity trends: - Conductivity (k) vs. Concentration (C) shows a
decreasing trend. - Molar Conductivity (Lambda_m) vs. Concentration (C) shows an increasing trend
for weak electrolytes.

6. Conclusion
The variation of conductivity and molar conductivity with concentration provides insights into ion
interactions and behavior in solutions. Understanding these properties is crucial for applications
in electrochemistry and industries.