Molar conductivity
Variation of Conductivity and Molar Conductivity with Concentration
Molar conductivity
o
It is denoted by the symbol. It is related to the conductivity of the solution by the following equation:
o The units of is S m 2 mol-1.
Problem:
THE CONDUCTIVITY OF 0.20 M SOLUTION OF KCL AT 298 K IS 0.0248 SCM-1. CALCULATE ITS MOLAR CONDUCTIVITY.
Solution: k = 0.0248 S cm- 1 c = 0.20 M Molar conductivity, Λm =( k x 1000) / c
= 0.0248 x1000 / 0.20 = 124 Scm 2 mol- 1
Variation of Conductivity and Molar Conductivity with Concentration
o
They depend on the concentration of the electrolyte. The Conductivity and Molar Conductivity of both weak and strong electrolytes decreases with decrease in concentration as the number of ions per unit volume carrying the current in a solution decreases on dilution.