Equilibrium Question 789
Question: The solubility of $ PbI_2 $ at $ 25{}^\circ C $ is $ 0.7g{L^{-1}} $ . The solubility product of $ PbI_2 $ at this temperature is (molar mass of $ PbI_2=461.2gmo{l^{-1}} $ )
Options:
A) $ 1.40\times {10^{-9}} $
B) $ 0.14\times {10^{-9}} $
C) $ 140\times {10^{-9}} $
D) $ 14.0\times {10^{-9}} $
Show Answer
Answer:
Correct Answer: D
Solution:
$ PbI_2\rightarrow \underset{s}{\mathop{P{b^{++}}}},+\underset{2s}{\mathop{2{I^{-}}}}, $
$ K _{sp}=s\times {{(2s)}^{2}}=4s^{3} $
$ =4\times {{( \frac{0.7}{461.2} )}^{3}}=14.0\times {10^{-9}} $
