The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below:


Concentration/M



0.001



0.010



0.020



0.050



0.100



102 × κ/S m–1



1.237



11.85



23.15



55.53



106.74



Calculate Λm for all concentrations and draw a plot between Λm and c1/2. Find the value of Λ0m.

(unit conversion factor)


Concentration (M)



κ (S m-1)



κ (S cm-1)



∧m = S cm2 mol-1





10-3



1.237×10-2



1.237×10-4





0.0316



10-2



11.85×10-2



11.85×10-4





0.100



2×10-2



23.15×10-2



23.15×10-4





0.141



5×10-2



55.53×10-2



55.53×10-4





0.224



10-1



106.74×10-2



106.74×10-4





0.316




∧0m = Intercept on the ∧m axis = 124.0 S cm2 mol-1, which is obtained by extrapolation to zero concentration.


10