Variation of conductivity with concentration

The variation of conductivity with concentration follows from what conductivity measures:

i. The electrolytic conductivity is the electrical conductance of unit volume ($\mathrm{1\ cm^3}$) of solution. It depends on the number of current-carrying ions present in unit volume of the solution.

ii. On dilution the total number of ions increases as a result of increased degree of dissociation.

iii. The increase in the total number of ions, however, is not in proportion to the dilution. Therefore the number of ions per unit volume of solution decreases — and this results in a decrease of conductivity with a decrease in the concentration of the solution. …