Question

The specific conductance of $AgCl$ solution in water was determined to be $1.8\times 10^{- 6}\Omega^{- 1}cm^{- 1}at298K$ . The molar conductances at infinite dilution of $Ag^{+}$ & $Cl^{-}$ are $67.9\&82.1\Omega^{- 1}1cm^{2}mol^{- 1}$ . What is the solubility of $AgCl$ in water ?

• A. $1.2\times 10^{- 8}M$
• B. $1.44\times 10^{- 10}M$
• C. $1.2\times 10^{- 5}M$
• D. $1.44\times 10^{- 16}M$

Answer 1

Answer: (C)

$\Lambda_{M \left(\right. AgCl \left.\right)}^{\infty }=\Lambda_{M \left(\left(Ag\right)^{+}\right)}^{\infty }+\Lambda_{M \left(\left(Cl\right)^{-}\right)}^{\infty }$
$=67.9+82.1$
$=150cm^{2}mol^{- 1}ohm^{- 1}$
$\Lambda_{M}^{\infty }=\frac{K \times 1000}{ S}$
$150=\frac{1 . 8 \times 10^{- 6} \times 10^{3}}{ S}$
$S=1.2\times 10^{- 5}M$