J.R. S. answered • 03/17/23
Tutor
5.0
(145)
Ph.D. University Professor with 10+ years Tutoring Experience
La(IO3)3(s) <==> La3+(aq) + 3IO3-(aq) .. dissolution equilibrium
Ksp = [La3+][IO3-]3
This is a common ion problem, where the common ion is La3+. Since the solution contains a high concentration of La3+ (0.200 M) relative to the amount of La3+ contributed by the La(IO3)3(s), we can use this as the [La3+] in the equation.
7.5x10-12 = [0.200] [IO3-]3
[IO3-]3 = 3.75x10-11
[IO3-] = 3.35x10-4 M
[La(IO3)3] = [IO3-] x 1 mol La(IO3)3 / 3 mol IO3- = 3.35x10-4 x 1 / 3 = 1.1x10-4 M
J.R. S.
tutor
Ah, yes. Carless mistake. Because the La(IO3)3 dissociates into La^3+ and 3IO3^-, the concentration of the original molecule will be 1/3 that of the IO3^- or 1.1x10^-4 M. I'll make the correction in the original answer.
Report
03/20/23
Halle C.
This is the concetration of the IO3 ion I am confused how to get the solubility of the whole La(IO3)303/20/23