Kohlrausch Law, also known as the Kohlrausch Law of Independent Migration, refers to an electrolytes limiting molar conductivity to its constituent ions. It indicates that an electrolytes limiting molar conductivity is equal to the sum of the individual limiting molar conductivities of the cations and anions that make up the electrolyte. The law was discovered by Friedrich Kohlrausch in 1875-1879 after observing experimental data on conductivities of various electrolytes.

Kohlrauschs law is used to determine an electrolytes dissociation constant, find out what a weak electrolytes limiting molar conductivity is, and determine the degrees of dissociation of weak electrolytes. It is also used to calculate molar conductivity at infinite dilution for weak electrolytes, which is difficult or impossible to calculate directly.

For any electrolyte AxBy, the limiting molar conductivity is expressed as x times the limiting molar conductivity of Ay+ and y times the limiting molar conductivity of Bx− . Kohlrauschs law is valid for low electrolyte concentrations only.