What is the solubility of AgBr in a solution of AgBr and AgSCN? Given rarr K_("sp AgSCN") =10^(-12) K_("sp AgBr")=5xx10^(-13) Thank you:)
2 Answers
Explanation:
I would represent the dissociated ions in equal amounts as they are in equilibrium.
Well, if the solution contains both, then since concentration is a state function, we can construct two sequential reactions.
"AgSCN"(s) rightleftharpoons "Ag"^(+)(aq) + "SCN"^(-)(aq)
"AgBr"(s) rightleftharpoons "Ag"^(+)(aq) + "Br"^(-)(aq)
We can define the solubility of
Assuming the solution was saturated with
The ICE Table would give for
5 xx 10^(-13) = ["Ag"^+]["Br"^-] = (10^(-6) + s)s
=> color(blue)(s = ["Ag"^(+)])
= color(blue)(3.66 xx 10^(-7) "M") (The solution with the small s approximation is
5.00 xx 10^(-7) "M" , which is 36.6% error, so the approximation would not be good.)
This is in contrast to its solubility by itself:
"Solubility"_("AgBr"(s,"pure")) = sqrt(5 xx 10^(-13))
= 7.07 xx 10^(-7) "M"
So the solubility of