A solution with a volume of 1·00 dm3 is saturated with lead iodide, Pbl2. The concentration of iodide ions is 2·7 mol dm–3.Determine the solubility product of PbI2. 

Answer 1

This is a common ion problem.
.....PbI2 ==> Pb^2+ + 2I^-
I....solid....0.......0
C....solid....x.......2x
E....solid....x.......2

Ksp = (Pb^2+)(I^-)^2
Ksp = ?
(I^-_ is 2.7 M.
(Pb^2+) = 1/2 (I^-)
Substitute and solve for Ksp.