What Is Molar Conductivity?

Molar conductivity is the conductivity of a solution divided by the electrolyte's molar concentration, explains DictionaryOfEngineering.com. It is a measure of the efficiency of the electrolyte in conducting electricity upon dissolution. The units of molar conductivity are Siemens per meter per mole.

In strong electrolytes, which readily dissociate in water, the concentration of the electrolyte has a weak effect on the molar conductivity of the solution. However, in weak electrolytes, which dissociate to a lesser extent in water, the concentration of the electrolyte affects the molar conductivity greatly. In these types of solutions, strong electrolytes are the better conductor of electricity.

Molar conductivity is a constant that differs for each compound as it dissolves in water. It includes the sum of the anion and cation molar conductivity. These theoretical values are based on the conductivity of a single molecule in an infinite amount of water, which scientists call an infinitely diluted solution.

Friedrich Kohlrausch receives credit for much of the work concerning electrolytes in solution. His work demonstrates that an electrolyte has a constant amount of resistance. It allows determination of the ion's transfer velocity in solution. His work with acids, salts and other ions shows that each ion has a particular resistance regardless of the compound that donates it to the solution.