Chemistry - Electrochemistry Question with Solution | TestHub

Molar conductivity (${\Lambda }_m$) is defined as the conducting power of all the ions produced by dissolving one mole of an electrolyte in a solution.

Mathematically, it is given by:
${\Lambda }_m=\frac{\kappa }{C}$

Where $\kappa$ is the conductivity with common units of ${\text{ohm}}^{-1}{\text{ cm}}^{-1}$ (or ${\text{S cm}}^{-1}$) and $C$ is the concentration expressed in ${\text{mol cm}}^{-3}$.

Substituting the units, we get:
${\Lambda }_m=\frac{{\text{ohm}}^{-1}{\text{ cm}}^{-1}}{{\text{mol cm}}^{-3}}={\text{ohm}}^{-1}{\text{ cm}}^2{\text{ mol}}^{-1}$

Thus, the common unit of molar conductivity is ${\text{ohm}}^{-1}{\text{ cm}}^2{\text{ mol}}^{-1}$.

Answer: ${\text{ohm}}^{-1}{\text{ cm}}^2{\text{ mol}}^{-1}$