Equilibrium Question 195
Question: The solubility product of $ Ag_2CrO_4 $ is $ 32\times {10^{-12}} $ . What is the concentration of $ CrO_4^{-} $ ions in that solution [BHU 1997; DPMT 2004]
Options:
A) $ 2\times {10^{-4}},m/s $
B) $ 16\times {10^{-4}},m/s $
C) $ 8\times {10^{-4}},m/s $
D) $ 8\times {10^{-8}},m/s $
Show Answer
Answer:
Correct Answer: A
Solution:
$ \underset{S}{\mathop{AgCrO_4}},\to \underset{2S}{\mathop{2A{g^{+}}}},+\underset{S}{\mathop{CrO_4^{–}}}, $
$ K _{sp}={{(2S)}^{2}}S=4S^{3} $
$ S={{( \frac{K _{sp}}{4} )}^{\frac{1}{3}}} $
$ ={{( \frac{32\times {10^{-12}}}{4} )}^{\frac{1}{3}}} $
$ =2\times {10^{-4}} $ M.
