Question

If the concentration of $CrO _{4}^{2-}$ ions in a saturated solution of silver chromate is $2 \times 10^{-4} M$, the solubility product of silver chromate would be

• A. $ 32\times 10^{-12}$
• B. $ 8\times 10^{-12}$
• C. $ 16\times 10^{-12}$
• D. $ 8\times 10^{-8}$

Answer 1

Answer: (A)

$Ag _{2} \underset{s}{CrO _{4}}(s) \rightleftharpoons \underset{2s}{2 Ag ^{+}}+ \underset{s}{CrO _{4}^{2-}}$
Given, ${\left[ CrO _{4}^{2-}\right]} =s= \times 10^{-4}$
$\therefore \left[ Ag ^{+}\right] =2 s=2 \times 2 \times 10^{-4}$
$=4 \times 10^{-4}$
$K_{ sp } =\left[ Ag ^{+}\right]^{2}\left[ CrO _{4}^{2-}\right]$
$=\left[4 \times 10^{-4}\right]^{2}\left[2 \times 10^{-4}\right]$
$=32 \times 10^{-12}$