Kohlrausch's Law

Kohlrausch's Law of Independent Migration of Ions states that at infinite dilution, where dissociation is complete, each ion makes a definite contribution to the total molar conductivity, regardless of the nature of the other ion.

• Formula: ${\Lambda }_m^{\circ }={\nu }_{+}{\lambda }_{+}^{\circ }+{\nu }_{-}{\lambda }_{-}^{\circ }$
• ${\lambda }_{+}^{\circ },{\lambda }_{-}^{\circ }$ are limiting molar conductivities of cations and anions.
• ${\nu }_{+},{\nu }_{-}$ are the number of cations and anions produced by one formula unit of the salt.
• Therefore, the total molar conductivity is the sum of the individual ionic conductivities.