Question

Define limiting molar conductivity.

Answer 1

The molar conductivity at infinite dilution or approx zero concentration is considered at limiting molar conductivity.

The limiting molar conductivity of strong electrolyte can be determined by the extrapolate of molar conductivity andb concentration curve but not possible for weak electrolyte by the same way.

In the case of strong electrolytes the value of molar conductance at infinite dilution is much less than unity.

Onsager was able to derive a theoretical expression to account for the empirical relation known as Kohlrausch's Law, for the molar conductivity, Λm.







is known as the limiting molar conductivity, K is an empirical constant and c is the electrolyte concentration Limiting here means "at the limit of the infinite dilution"). 

Answer 2

Molar conductivity is defined as the conductivity of an electrolyte solution divided by the molar concentration of the electrolyte, and so measures the efficiency with which a given electrolyte conducts electricity in solution. It is the conducting power of all the ions produced by dissolving one mole of an electrolyte in solution. Its units are siemens per meter per molarity, or siemens meter-squared per mole. The usual symbol is a capital lambda, Λ, or Λm. It can also be defined as follows: Molar conductivity of a solution at a given concentration is the conductance of the volume (V) of the solution containing one mole of electrolyte kept between two electrodes with area of cross section (A) and at a distance of unit length.