Question

State Kohlrausch law of independent migration of ions. Give its applications. Write an expression for the molar conductivity of acetic acid at infinite dilution.

Answer 1

Kohlrausch Law of Independent Migration of Ions:

The limiting molar conductivity of an electrolyte is equal to the sum of the individual contributions of the anion and cation of the electrolyte.

If λ°(Na+) and λ°(Cl-) are the limiting molar conductivities of sodium and chloride ions, then limiting molar conductivity of NaCl is:

Λ°m(NaCl) = λ°(Na+) + λ°(Cl-)

Applications of Kohlrausch Law are as follows:

• Calculation of the limiting molar conductivity of an electrolyte.

• Calculation of the degree of dissociation of weak electrolytes.

- The expression for the molar conductivity of acetic acid can be given as follows:

Λ°m(CH3COOH) = λ°(CH3COO-) + λ°(H+)