Chemistry - Electrochemistry Question with Solution | TestHub

In an extensive series of measurements during the nineteenth century, Friedrich Kohlrausch showed that at low concentrations the molar conductivities of strong electrolytes vary linearly with the square root of the concentration :

$${\Lambda }_m={\Lambda }_m^{\circ }-K\sqrt{c}$$

This variation is called Kohlrausch's law. The constant ${\Lambda }_m^{\circ }$ is the limiting molar conductivity, which is the molar conductivity in the limit of zero concentration.

If the molar conductivity of a 0.01 M KCl solution is given as 140 S cm² mol⁻¹.

Given:

${\Lambda }_m^{\circ }(C{l}^{-})=76.35Sc{m}^{2}mo{l}^{-1}$,

${\Lambda }_m^{\circ }(K^{+})=73.65Sc{m}^{2}mo{l}^{-1}$,

${\Lambda }_m^{\circ }(N{a}^{+})=49.65Sc{m}^{2}mo{l}^{-1}$.

Calculate the molar conductivity of a 0.04 M NaCl solution.