Question

What is the relationship between molar conductivity and specific conductivity?

How is molar conductivity of a solution related to its specific conductivity?

Write expressions showing the mutual relationship between molar and specific conductivities.

Answer 1

The molar conductivity (Λ_m) is related to the specific conductivity (κ) by the following equation:

Λ_m = `kappa/c_m`    ...(i)

where c_m is the solution’s concentration expressed in moles per volume unit.

If one mole of an electrolyte is dissolved in V_m cm³ of the solution, we have

c_m = `1/V_m` mol cm⁻³

Therefore, from the equation (i), we have

Λ_m = κ × V_m     ...(ii)

It should be carefully noted that the volume in cm³ of the solution containing one mole of the electrolyte is represented by the word V_m in the equation above.