Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

Explanation

Conductivity: Conductivity of solution is defined as the conductance of the solution present between two opposite faces of a one centimetre cube. Units of conductiivity are `ohm^(-1) cm^(-1) or S cm^(-1)` or mho `cm^(-1)`.
Molar conductivity: Molar conductivity is defined as the conductance of a solution containing 1 gram mole of the electrolyte placed between two plates kept 1 cm apart. units of molar conductivity are `ohm^(-1)mol^(-1) or Scm^(-1)` or mho `cm^(2)mol^(-1)`.
Effect of Dilution on Molar conductivity and Conductivity.
In case of strong electrolytes the molar conductivity increases slightly with dilution, as mobility of ions increases. in case of weak electrolytes the degree of ionisation increases with dilution, therefore, there is a large increase in molar conductivity with dilution.
Conductivity is conductance of the solution present between the between two opposite faces of one centimetre cube. on dilution, number of ions per `cm^(3)` decreases therefore conductivity decreases on dilution.