Question

The solubility of $ Sb_{2}S_{3} $ , in water is $ 1.0\times 10^{-5} $ $ mol/L $ at $ 298\,\,K $ . What will be its solubility product?

• A. $ 108\times 10^{-25} $
• B. $ 1.0\times 10^{-25} $
• C. $ 114\times 10^{-25} $
• D. $ 126\times 10^{-24} $

Answer 1

Answer: (A)

$\underset{s\,mol/L}{Sb_2S_3} \ce{<=>} \underset{2s}{2Sb^{3+}} + \underset{3s}{3S^{2-}}$
Solubility product $(K_{sp}) = [Sb^{3+}][S^{2-}]^3$
$=(2 s)^{2}(3 s)^{3}=108 s^{5}$
$=108 \times\left(1.0 \times 10^{-5}\right)^{5}=108 \times 10^{-25}$