Question

In a sautrated solution of the sparingly soluble strong electrolyte $AgIO_3$ (Molecular mass $= 283$) the equilibrium which sets in is
$AgIO_{3(s)} \rightleftharpoons Ag^+_{(aq)} +IO^{-}_{3(aq)}$
If the solubility product constant $K_{sp}$ of $AgIO_3$ at a given temperature is $1.0 × 10^{−8}$, what is the mass of $AgIO_3$ contained in $100\, ml$ of its saturated solution?

• A. $28.3 × 10^{−2}\, g$
• B. $28.3 × 10^{−3}\, g$
• C. $1.0 × 10^{−7}\, g$
• D. $1.0 × 10^{−4}\, g$

Answer 1

Answer: (B)

$AgIO_{3(s)} \rightleftharpoons Ag^+_{(aq)} +IO^{-}_{3(aq)}$
Let the solubility of $AgIO_3$ be s
$K_{sp}=\left[Ag^{+}\right]\left[IO^{-}_{3}\right]$
$1.0\times10^{-8}=S^{2}$
$S=10^{-4}\,mol/litre$
$=\frac{10^{-4}\times283}{1000}\times100$
$=283\times10^{-5}$
$=2.83\times10^{-3}\,g/ 100\, ml$
Hence, (2) is correct.