Question

The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm-1. Calculate its molar conductivity.​

Answer 1

Given:

Conductivity (k) = 0.0248 S/cm

Molarity (M) = 0.20 M

To Find:

Molar conductivity $\rm ( \Lambda_m)$

Answer:

MOLAR CONDUCTIVITY

The molar conductivity of an electrolyte in solution is defined as the conductance of a solution containing one mole of the electrolyte. It is related to the concentration by the following relation:

$\boxed{ \bf \Lambda_m = \dfrac{k \times 1000}{Molarity} \ Scm^{2}mol^{-1}}$

By substituting values we get:

$\rm \leadsto \Lambda_m = \dfrac{0.0248 \times 1000}{0.2} \\ \\ \rm \leadsto \Lambda_m = \dfrac{24.8}{0.2} \\ \\ \rm \leadsto \Lambda_m = 124 \: Scm^{2}mol^{-1}$

$\therefore$ Molar conductivity $\rm ( \Lambda_m)$ = 124 Scm²/mol