Question

The molar conductivities at infinite dilution of barium chloride, sulphuric arid and hydrochloric acid are 280,860 and $426Sc{m}^{2}mo{l}^{-1}$ respectively. The molar conductivity at infinite dilution of barium sulphate is _________ $Sc{m}^{2}mo{l}^{-1}$
(Round off to the Nearest Integer).

Answer 1

Answer: 288

From Kohlrausch' s law

${\Lambda }_m^{\infty }\left(BaS{O}_4\right)={\lambda }_m^{\infty }\left(B{a}^{2+}\right)+{\lambda }_m^{\infty }\left(S{O}_4^{2-}\right)$

${\Lambda }_m^{\infty }\left(BaS{O}_4\right)={\Lambda }_m^{\infty }\left(BaC{l}_2\right)+{\Lambda }_m^{\infty }\left(H_{2}S{O}_4\right)$

$-2{\Lambda }_m^{\infty }(HCl)$

$=280+860-2(426)$

$=288Sc{m}^{2}mo{l}^{-1}$