Question

The ionic conductance of $B{a}^{2+}$ and $C{l}^{-}$ are respectively $127$ and $76{\Omega }^{-1}$ $c{m}^2$ at infinite dilution. The equivalent conductance (in ${\Omega }^{-1}$ $c{m}^2$) of $BaC{l}_2$ at infinite dilution will be:

• A. $101.5$
• B. $203.5$
• C. $139.5$
• D. $279.5$

Answer 1

Answer: (C)

$139.5$

At infinite dilution the equivalnet conductance can be given as follow:

${\lambda }_{\infty }=\frac{1}{n^{+}}{\lambda }_{B{a}^{2+}}+\frac{1}{m^{-}}{\lambda }_{C{l}^{-}}$

where, $n^{+}$ and $m^{-}$ are the valency of cation and anion.

For, $BaC{l}_2$, $n^{+}=2$ and $m^{-}=1$

Thus, the equivalent conductance of $BaC{l}_2=\frac{1}{2}\times 127+76=139.5$