Kohlrausch's law definition

Kohlrausch's law of indendent migration of ions states that the molar conductance of infinite dilution (limiting molar conductivity ) is the sum of the individual contributions of the anions and cations of the electrolyte.

It can be given in the mathematical form as:
λ⁰_M = v₊λ⁰₊ + v_-λ⁰_-
λ⁰₊ and λ⁰_- are the limiting molar conductivity of cation and anion respectively.
For NaCl,
λ⁰_M = λ⁰_Na+ + λ⁰_Cl-
And for Al2(SO4)3,
λ⁰ _Al2(SO4)3 =2 λ⁰_Al3+ + λ⁰_{SO4 2-}