(a) 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 distance of unit length
where k is the conductivity and V is the volume of solution containing one mole of the electrolyte and C is the molar concentration. Molar conductivity increases with decrease in concentration or increase in dilution as the number of ions as well as the mobility of ions increases with increase in dilution. For strong electrolytes, the number of ions does not increase appreciably on dilution and only mobility of ions increases due to decrease in interionic attractions. Therefore, Am increases a little as shown in figure by a straight line. For weak electrolytes, number of ions as well as mobility of ions increases on dilution which results in a very large increase in molar conductivity, especially at infinite dilution (i.e., concentration, C → 0) as shown by curve in figure