The molar conductivities at infinite dilution of barium chloride,
Question:

The molar conductivities at infinite dilution of barium chloride, sulphuric arid and hydrochloric acid are 280,860 and $426 \mathrm{Scm}^{2} \mathrm{~mol}^{-1}$ respectively. The molar conductivity at infinite dilution of barium sulphate is ______________ .$\mathrm{Scm}^{2} \mathrm{~mol}^{-1}$ (Round off to the Nearest Integer).

Solution:

From Kohlrausch’s law

$\Lambda_{\mathrm{m}}^{\infty}\left(\mathrm{BaSO}_{4}\right)=\lambda_{\mathrm{m}}^{\infty}\left(\mathrm{Ba}^{2+}\right)+\lambda_{\mathrm{m}}^{\infty}\left(\mathrm{SO}_{4}^{2-}\right)$

$\Lambda_{\mathrm{m}}^{\infty}\left(\mathrm{BaSO}_{4}\right)=\Lambda_{\mathrm{m}}^{\infty}\left(\mathrm{BaCl}_{2}\right)+\Lambda_{\mathrm{m}}^{\infty}\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)$

$=280+860-2(426)$

$=288 \mathrm{Scm}^{2} \mathrm{~mol}^{-1}$