Equilibrium Question 756
Question: When equal volumes of the following solutions are mixed, precipitation of AgCl ( $ K _{sp} $ = $ 1.8\times {10^{-10}} $ ) will occur only with
Options:
A) $ {10^{-4}}M(A{g^{+}}),and,{10^{-4}}M(C{l^{-}}) $
B) $ {10^{-5}}M(A{g^{+}}),and,{10^{-5}}M(C{l^{-}}) $
C) $ {10^{-16}}M(A{g^{+}}),and,{10^{-6}}M(C{l^{-}}) $
D) $ {10^{-10}}M(A{g^{+}}),and,{10^{-10}}M(C{l^{-}}) $
Show Answer
Answer:
Correct Answer: A
Solution:
$ AgCl\rightarrow [A{g^{+}}]+[C{l^{-}}] $
$ =( \frac{{10^{-4}}\times V}{2V} )( \frac{{10^{-4}}\times V}{2V} )=2.5\times {10^{-9}} $
This value is greater than $ K _{sp}=1.8\times {10^{-10}} $
(2) IP= $ ( \frac{{10^{-5}}\times V}{2V} )( \frac{{10^{-5}}\times V}{2V} )=2.5\times {10^{-11}}<K _{sp} $
(3) IP= $ ( \frac{{10^{-16}}\times V}{2V} )( \frac{{10^{-6}}\times V}{2V} )=2.5\times {10^{-23}}<K _{sp} $
(4) IP= $ ( \frac{{10^{-10}}\times V}{2V} )( \frac{{10^{-10}}\times V}{2V} )=2.5\times {10^{-21}}<K _{sp} $
