Question

Define kohlrauchs law? give its applications?

Answer 1

Kohlrausch law :

This law states that the limiting molar conductivity of an electrolyte can be represented as the sum of the individual contributions of its anion and cation.

Λ∞m = λ∞+ + λ∞-

Where λ∞+ and λ∞- are the limiting equivalent conductivities of cation and anion respectively

Example:

The molar conductivity of HCl at infinite dilution can be expressed as,

Λ∞ HCl = λ∞ H + λ∞ Cl-

Applications of Kohlrausch 's law:

• Determination of Λ∞m for weak electrolytes
• Determination of the degree of ionization of a weak electrolyte
• Determination of the ionization constant of a weak electrolyte
• Determination of the solubility of a sparingly soluble salt